| 1 | Oakes Machine Operator |
| 2 | Oarsman |
| 3 | OB/GYN (Obstetrician / Gynecologist) |
| 4 | OB/GYN (Obstetrician Gynecologist) |
| 5 | OB/GYN Doctor (Obstetrics/Gynecology Doctor) |
| 6 | OB/GYN Nurse (Obstetrics/Gynecology Nurse) |
| 7 | OB/GYN Physician (Obstetrics and Gynecology Physician) |
| 8 | Obedience Trainer |
| 9 | OBGYN MD (Obstetrics Gynecology Medical Doctor) |
| 10 | OB-GYN NP (Obstetrics-Gynecology Nurse Practitioner) |
| 11 | Object-Oriented Programmer |
| 12 | Objects Conservator |
| 13 | Oboist |
| 14 | Observer |
| 15 | Obstetrical Anesthesiologist |
| 16 | Obstetrical Nurse |
| 17 | Obstetrician |
| 18 | Obstetrician/Gynecologist (OB/GYN) |
| 19 | Obstetricians and Gynecologists |
| 20 | Obstetrics Gynecology Physician (OB/GYN Physician) |
| 21 | Obstetrics Nurse (OB Nurse) |
| 22 | Obstetrics Scrub Nurse (OB Scrub Nurse) |
| 23 | Obstetrics Specialist (OB Specialist) |
| 24 | Obstetrics Teacher |
| 25 | Occupancy Director |
| 26 | Occupancy Specialist |
| 27 | Occupational Analyst |
| 28 | Occupational Ergonomist |
| 29 | Occupational Health and Safety Specialist |
| 30 | Occupational Health and Safety Specialists |
| 31 | Occupational Health and Safety Technician |
| 32 | Occupational Health and Safety Technicians |
| 33 | Occupational Health and Safety Technologist |
| 34 | Occupational Health and Safety Technologist (OHST) |
| 35 | Occupational Health Nurse |
| 36 | Occupational Health Nursing Director |
| 37 | Occupational Health Physician |
| 38 | Occupational Medicine Officer |
| 39 | Occupational Medicine Physician |
| 40 | Occupational Nurse |
| 41 | Occupational Physician |
| 42 | Occupational Psychologist |
| 43 | Occupational Rehabilitation Aide |
| 44 | Occupational Safety and Health Inspector |
| 45 | Occupational Therapist (OT) |
| 46 | Occupational Therapist Aide (OT Aide) |
| 47 | Occupational Therapist Assistant (OTA) |
| 48 | Occupational Therapists |
| 49 | Occupational Therapy Aide (OT Aide) |
| 50 | Occupational Therapy Aides |
| 51 | Occupational Therapy Aides Teacher |
| 52 | Occupational Therapy Assistant (OTA) |
| 53 | Occupational Therapy Assistants |
| 54 | Occupational Therapy Director |
| 55 | Occupational Therapy Professor |
| 56 | Occupational Therapy Teacher |
| 57 | Occupational Therapy Technician |
| 58 | Ocean Biologist |
| 59 | Ocean Export Agent |
| 60 | Ocean Export Clerk |
| 61 | Ocean Export Coordinator |
| 62 | Ocean Forwarder |
| 63 | Ocean Freight Customer Relations Specialist |
| 64 | Ocean Freight Forwarder |
| 65 | Ocean Import Representative |
| 66 | Ocean Import Specialist |
| 67 | Ocean Lifeguard |
| 68 | Ocean Lifeguard Specialist |
| 69 | Ocean Program Administrator |
| 70 | Ocean Transportation Intermediary |
| 71 | Oceanic Sciences Professor |
| 72 | Oceanographer |
| 73 | Oceanographic Meteorologist |
| 74 | Oceanography Professor |
| 75 | Oceanography Teacher |
| 76 | Oceanologist |
| 77 | Oceanology Teacher |
| 78 | Octave Board Assembler |
| 79 | Ocular Care Aide |
| 80 | Ocular Care Technician (Ocular Care Tech) |
| 81 | Ocular Care Technologist |
| 82 | Ocular Pathologist |
| 83 | Oculoplastic Specialist |
| 84 | OD Grinder Operator (Outer Diameter Grinder Operator) |
| 85 | Odd Bundle Worker |
| 86 | Odd Job Laborer |
| 87 | Odd Jobs Day Worker |
| 88 | Odd Shoe Examiner |
| 89 | Odd-Piece Checker |
| 90 | OEC Tech (Outdoor Emergency Care Technician) |
| 91 | Offal Roller |
| 92 | Offal Separator |
| 93 | Offal Trimmer |
| 94 | Offal Worker |
| 95 | Offbearer |
| 96 | Offender Employment Specialist (OES) |
| 97 | Offender Job Retention Specialist |
| 98 | Offender Workforce Development Program Manager (OWDPM) |
| 99 | Offender Workforce Development Specialist (OWDS) |
| 100 | Office Administrator |
| 101 | Office Aide |
| 102 | Office Assistant |
| 103 | Office Associate |
| 104 | Office Automation Clerk |
| 105 | Office Automation Technician |
| 106 | Office Bookkeeper |
| 107 | Office Cleaner |
| 108 | Office Clerical Helper |
| 109 | Office Clerk |
| 110 | Office Clerks, General |
| 111 | Office Coordinator |
| 112 | Office Copy Selector |
| 113 | Office Correspondent |
| 114 | Office Electrician |
| 115 | Office Employee |
| 116 | Office Equipment Installer |
| 117 | Office Helper |
| 118 | Office Machine Components Inspector |
| 119 | Office Machine Embossograph Operator |
| 120 | Office Machine Installer |
| 121 | Office Machine Mechanic |
| 122 | Office Machine Operators, Except Computer |
| 123 | Office Machine Punch Operator |
| 124 | Office Machine Service Supervisor |
| 125 | Office Machine Servicer |
| 126 | Office Machinery Installer |
| 127 | Office Machines Sales Representative |
| 128 | Office Machines Teacher |
| 129 | Office Machines Wirer |
| 130 | Office Manager |
| 131 | Office Materials Sales Representative |
| 132 | Office Messenger |
| 133 | Office Messenger Helper |
| 134 | Office Nurse |
| 135 | Office Rental Clerk |
| 136 | Office Runner |
| 137 | Office Secretary |
| 138 | Office Services Specialist |
| 139 | Office Services Supervisor |
| 140 | Office Supervisor |
| 141 | Office Support Assistant |
| 142 | Office Sweeper |
| 143 | Office System Analyst |
| 144 | Office Technician |
| 145 | Office Technology Instructor |
| 146 | Office Worker |
| 147 | Officer |
| 148 | Officer in Charge of Engineering Watch (OICEW) |
| 149 | Official Court Reporter |
| 150 | Official Greeter |
| 151 | Offline Cutter |
| 152 | Offset Duplicating Machine Operator |
| 153 | Offset Duplicating Machine Set Up Operator |
| 154 | Offset Label Rewinder |
| 155 | Offset Lithographic Press Operator |
| 156 | Offset Lithographic Press Setter |
| 157 | Offset Lithographic Press Setup Operator |
| 158 | Offset Lithographic Set-Up Operator |
| 159 | Offset Machine Operator |
| 160 | Offset Plate Maker |
| 161 | Offset Plate Preparation Supervisor |
| 162 | Offset Platemaker |
| 163 | Offset Press Operator |
| 164 | Offset Pressman |
| 165 | Offset Printer |
| 166 | Offset Printing Operator |
| 167 | Offset-Press Operator |
| 168 | Offshore Energy Environmental Manager |
| 169 | Offshore Wind Operations Manager |
| 170 | Offshore Wind Turbine Technician |
| 171 | Offshoring Manager |
| 172 | Oil Analyst |
| 173 | Oil and Gas Equipment Operator |
| 174 | Oil and Gas Exploration Technician |
| 175 | Oil and Gas Field Technician |
| 176 | Oil and Gas Operations Management Professional |
| 177 | Oil and Gas Specialist |
| 178 | Oil and Shale and Tar Processing Technician |
| 179 | Oil Bay Technician |
| 180 | Oil Boiler |
| 181 | Oil Burner |
| 182 | Oil Burner Installer |
| 183 | Oil Burner Journeyman |
| 184 | Oil Burner Mechanic |
| 185 | Oil Burner Repairer |
| 186 | Oil Burner Servicer |
| 187 | Oil Burner Servicer and Installer Helper |
| 188 | Oil Burner Technician (Oil Burner Tech) |
| 189 | Oil Changer |
| 190 | Oil Deliverer |
| 191 | Oil Derrick Operator |
| 192 | Oil Dispatcher |
| 193 | Oil Distributor |
| 194 | Oil Distributor Tender |
| 195 | Oil Drafter |
| 196 | Oil Driller |
| 197 | Oil Drilling Engineer |
| 198 | Oil Expert |
| 199 | Oil Exploration Engineer |
| 200 | Oil Field Equipment Mechanic |
| 201 | Oil Field Equipment Mechanic Supervisor |
| 202 | Oil Field Laborer |
| 203 | Oil Field Operator |
| 204 | Oil Field Plant Operator |
| 205 | Oil Field Pumper |
| 206 | Oil Field Rig Builder |
| 207 | Oil Field Roustabout |
| 208 | Oil Field Supplies and Equipment Sales Representative |
| 209 | Oil Field Technician |
| 210 | Oil Field Tester |
| 211 | Oil Field Worker |
| 212 | Oil Filters Inspector |
| 213 | Oil Fire Specialist |
| 214 | Oil Floorhand |
| 215 | Oil Furnace Installer |
| 216 | Oil Gauger |
| 217 | Oil Heat Technician (Oil Heat Tech) |
| 218 | Oil Heater Installer |
| 219 | Oil Heater Operator |
| 220 | Oil Heaterman |
| 221 | Oil House Attendant |
| 222 | Oil Inspector |
| 223 | Oil Laboratory Analyst |
| 224 | Oil Lease Buyer |
| 225 | Oil Lease Operator |
| 226 | Oil Mixer |
| 227 | Oil Movements Operator |
| 228 | Oil Painter |
| 229 | Oil Pipe Inspector |
| 230 | Oil Pipeline Dispatcher |
| 231 | Oil Pipeline Operator |
| 232 | Oil Pit Attendant |
| 233 | Oil Processing Technician |
| 234 | Oil Prospecting Observer |
| 235 | Oil Pumper |
| 236 | Oil Recovery Operator |
| 237 | Oil Recovery Unit Operator |
| 238 | Oil Refiner |
| 239 | Oil Refinery Process Technician |
| 240 | Oil Rig Driller |
| 241 | Oil Rig Floorhand |
| 242 | Oil Rig Roughneck |
| 243 | Oil Rigger |
| 244 | Oil Scout |
| 245 | Oil Separator |
| 246 | Oil Spot Washer |
| 247 | Oil Spreader Operator |
| 248 | Oil Tank Car Cleaner |
| 249 | Oil Tanker Captain |
| 250 | Oil Tester |
| 251 | Oil Transport Driver |
| 252 | Oil Treater |
| 253 | Oil Truck Driver |
| 254 | Oil Well Cable Tool Driller |
| 255 | Oil Well Cable Tool Operator |
| 256 | Oil Well Directional Surveyor |
| 257 | Oil Well Driller |
| 258 | Oil Well Engineer |
| 259 | Oil Well Fishing Tool Technician |
| 260 | Oil Well Gun Perforator Operator |
| 261 | Oil Well Logger |
| 262 | Oil Well Perforator Operator |
| 263 | Oil Well Pumper |
| 264 | Oil Well Service Operator |
| 265 | Oil Well Service Operator Helper |
| 266 | Oil Well Service Unit Operator |
| 267 | Oil Well Services Dispatcher |
| 268 | Oil Well Services Field Supervisor |
| 269 | Oil Well Services Supervisor |
| 270 | Oil Well Shooter |
| 271 | Oiler |
| 272 | Oiler Bander |
| 273 | Oilfield Plant Operator |
| 274 | Oilseed Meat Presser |
| 275 | Old Coin Dealer |
| 276 | Old Testament Professor |
| 277 | Older Adult Social Work Specialist |
| 278 | Older Worker Specialist |
| 279 | Oleomargarine Maker |
| 280 | Olericulture Professor |
| 281 | Olericulture Teacher |
| 282 | Olive Brine Tester |
| 283 | Olive Grader |
| 284 | Olive Knocker |
| 285 | Olive Packer |
| 286 | Olive Picker |
| 287 | Oliver Filter Operator |
| 288 | Oliving Machine Operator |
| 289 | Ombudsman |
| 290 | On Car Supervisor |
| 291 | On-Air Announcer |
| 292 | On-Air Director |
| 293 | On-Air Personality |
| 294 | Oncologist |
| 295 | Oncology Art Therapist |
| 296 | Oncology Bioinformatics Analyst |
| 297 | Oncology Dietitian |
| 298 | Oncology Nurse |
| 299 | Oncology Physician |
| 300 | Oncology RN (Oncology Registered Nurse) |
| 301 | Oncology Social Worker |
| 302 | Onion Tier |
| 303 | Onion Topper |
| 304 | Online Advertising Director |
| 305 | Online Content Coordinator |
| 306 | Online Content Developer |
| 307 | Online Content Editor |
| 308 | Online Editor |
| 309 | Online English Instructor |
| 310 | Online History Instructor |
| 311 | Online Marketing Consultant |
| 312 | Online Marketing Strategist |
| 313 | Online Merchant |
| 314 | Online Merchants |
| 315 | Online Philosophy Instructor |
| 316 | Online Producer |
| 317 | Online Publisher |
| 318 | Online Retailer |
| 319 | Online Services Manager |
| 320 | Online Trader |
| 321 | Online Tutor |
| 322 | Online User Experience Strategist |
| 323 | On-Scene Supporter |
| 324 | Onsite Coordinator |
| 325 | On-Site Manager |
| 326 | Onsite Services Specialist |
| 327 | On-Site Services Specialist |
| 328 | On-Site Wastewater Systems Technician |
| 329 | Onyx-Chip Terrazzo Worker |
| 330 | Opaquer |
| 331 | Open Claims Representative (OCR) |
| 332 | Open Developer Operator |
| 333 | Open Die Inspector |
| 334 | Open Hearth Furnace Operator |
| 335 | Open Hearth Helper |
| 336 | Open Hearth Melter |
| 337 | Open Hearth Stockyard Supervisor |
| 338 | Open Hearth Worker |
| 339 | Open Pit Quarry Supervisor |
| 340 | Open Winder |
| 341 | Opener |
| 342 | Opera Singer |
| 343 | Operating Engineer |
| 344 | Operating Engineers and Other Construction Equipment Operators |
| 345 | Operating Marine Engineer |
| 346 | Operating Power Plant Combustion Engineer |
| 347 | Operating Room Aide |
| 348 | Operating Room Assistant |
| 349 | Operating Room Orderly |
| 350 | Operating Room Registered Nurse (OR RN) |
| 351 | Operating Room Surgical Technician (OR St) |
| 352 | Operating Room Surgical Technologist |
| 353 | Operating Room Technician |
| 354 | Operating Room Technician (OR Tech) |
| 355 | Operating Room Technologist (OR Tech) |
| 356 | Operating System Programmer |
| 357 | Operating Systems Specialist |
| 358 | Operating Technician (Operating Tech) |
| 359 | Operation Specialist |
| 360 | Operational Meteorologist |
| 361 | Operational Risk Manager |
| 362 | Operational Test Mechanic |
| 363 | Operations Administrator |
| 364 | Operations Agent |
| 365 | Operations Analyst |
| 366 | Operations and Maintenance Manager (O&M Manager) |
| 367 | Operations and Maintenance Specialist (O&M Specialist) |
| 368 | Operations and Maintenance Technician (O & M Technician) |
| 369 | Operations and Maintenance Technician (O and M Technician) |
| 370 | Operations Assistant |
| 371 | Operations Chief |
| 372 | Operations Clerk |
| 373 | Operations Coordinator |
| 374 | Operations Director |
| 375 | Operations Engineer |
| 376 | Operations Forester |
| 377 | Operations Inspector |
| 378 | Operations Label Clerk |
| 379 | Operations Logistics Analyst |
| 380 | Operations Manager |
| 381 | Operations Officer |
| 382 | Operations Representative |
| 383 | Operations Research Analyst |
| 384 | Operations Research Analysts |
| 385 | Operations Specialist |
| 386 | Operations Superintendent |
| 387 | Operations Supervisor |
| 388 | Operations Support Technician |
| 389 | Operations Technician |
| 390 | Operations Technician (Operations Tech) |
| 391 | Operations Vice President (Operations VP) |
| 392 | Operator |
| 393 | Operator Engineer |
| 394 | Operator Technician |
| 395 | Operators School Manager |
| 396 | Ophthalmic Aide |
| 397 | Ophthalmic Assistant |
| 398 | Ophthalmic Diagnostic Imager |
| 399 | Ophthalmic Diagnostic Sonographer |
| 400 | Ophthalmic Dispenser |
| 401 | Ophthalmic Echographer |
| 402 | Ophthalmic Laboratory Technicians |
| 403 | Ophthalmic Medical Assistant |
| 404 | Ophthalmic Medical Technician (Ophthalmic Medical Tech) |
| 405 | Ophthalmic Medical Technicians |
| 406 | Ophthalmic Medical Technologist (Ophthalmic Medical Tech) |
| 407 | Ophthalmic Medical Technologists |
| 408 | Ophthalmic Pathologist |
| 409 | Ophthalmic Photographer |
| 410 | Ophthalmic Sonographer |
| 411 | Ophthalmic Surgeon |
| 412 | Ophthalmic Surgical Coordinator |
| 413 | Ophthalmic Technician |
| 414 | Ophthalmic Technologist (Ophthalmic Tech) |
| 415 | Ophthalmic Ultrasonographer |
| 416 | Ophthalmological Assistant |
| 417 | Ophthalmologist |
| 418 | Ophthalmologist Specialist |
| 419 | Ophthalmologists, Except Pediatric |
| 420 | Ophthalmology Assistant |
| 421 | Ophthalmology Technician (Ophthalmology Tech) |
| 422 | Opinion Polls Survey Worker |
| 423 | Optical Astronomer |
| 424 | Optical Coating Technician |
| 425 | Optical Design Engineer |
| 426 | Optical Dispenser |
| 427 | Optical Effects Camera Operator |
| 428 | Optical Effects Layout Person |
| 429 | Optical Element Coater |
| 430 | Optical Engineer |
| 431 | Optical Engineering Technician |
| 432 | Optical Fabrication Technician |
| 433 | Optical Glass Etcher |
| 434 | Optical Glass Inspector |
| 435 | Optical Glass Sawyer |
| 436 | Optical Glass Silverer |
| 437 | Optical Glass Wet Inspector |
| 438 | Optical Goods Drill Operator |
| 439 | Optical Goods Drilling Machine Operator |
| 440 | Optical Instrument Assembler |
| 441 | Optical Instrument Assembly Supervisor |
| 442 | Optical Instrument Inspector |
| 443 | Optical Instruments Supervisor |
| 444 | Optical Lab Technician (Optical Laboratory Technician) |
| 445 | Optical Laboratory Mechanic |
| 446 | Optical Lathe Operator |
| 447 | Optical Manufacturing Technician |
| 448 | Optical Mechanic |
| 449 | Optical Network Engineer |
| 450 | Optical Scientist |
| 451 | Optical Specialist |
| 452 | Optical Systems Engineer |
| 453 | Optical Technician |
| 454 | Optical Worker |
| 455 | Optician |
| 456 | Opticianry Teacher |
| 457 | Opticians, Dispensing |
| 458 | Optics Engineer |
| 459 | Optics Manufacturing Technician |
| 460 | Optics Test Technician |
| 461 | Optimization Analyst |
| 462 | Options Advisor |
| 463 | Options Trader |
| 464 | Optoelectronic Technician |
| 465 | Optoelectronics Engineer |
| 466 | Optomechanical Engineer |
| 467 | Optomechanical Technician |
| 468 | Optometric Aide |
| 469 | Optometric Assistant |
| 470 | Optometric Prescreener |
| 471 | Optometric Technician |
| 472 | Optometric Technician (Optometric Tech) |
| 473 | Optometric Technologist |
| 474 | Optometrist |
| 475 | Optometrist Assistant |
| 476 | Optometrists |
| 477 | Optometry Assistant |
| 478 | Optometry Doctor (OD) |
| 479 | Optometry Professor |
| 480 | Optometry Teacher |
| 481 | OR Nurse (Operating Room Nurse) |
| 482 | OR Pharmacy Tech (Operating Room Pharmacy Tech) |
| 483 | Oracle Database Administrator |
| 484 | Oral and Maxillofacial Surgeon (OMS) |
| 485 | Oral and Maxillofacial Surgeons |
| 486 | Oral Historian |
| 487 | Oral Hygienist |
| 488 | Oral Maxillofacial Prosthodontist |
| 489 | Oral Pathologist |
| 490 | Oral Surgeon |
| 491 | Oral Surgery Assistant |
| 492 | Oral Therapist |
| 493 | Orange Picker |
| 494 | Orange Picker Machine Operator |
| 495 | Orchard Hand |
| 496 | Orchard Manager |
| 497 | Orchard Sprayer |
| 498 | Orchard Worker |
| 499 | Orchestra Conductor |
| 500 | Orchestra Director |
| 501 | Orchestra Leader |
| 502 | Orchestra Musician |
| 503 | Orchestra Teacher |
| 504 | Orchestrator |
| 505 | Orchid Hand |
| 506 | Orchid Transplanter |
| 507 | Ordained Minister |
| 508 | Order Administrator |
| 509 | Order Analyst |
| 510 | Order Associate |
| 511 | Order Booker |
| 512 | Order Builder |
| 513 | Order Builder Loader |
| 514 | Order Caller |
| 515 | Order Checker |
| 516 | Order Clerk |
| 517 | Order Clerks |
| 518 | Order Department Supervisor |
| 519 | Order Desk Clerk |
| 520 | Order Detailer |
| 521 | Order Dispatcher |
| 522 | Order Editor |
| 523 | Order Entry Administrator |
| 524 | Order Entry Clerk |
| 525 | Order Entry Representative |
| 526 | Order Entry Specialist |
| 527 | Order Expediter |
| 528 | Order Filler |
| 529 | Order Fulfillment Specialist |
| 530 | Order Loader |
| 531 | Order Make Up Clerk |
| 532 | Order Packager |
| 533 | Order Packer |
| 534 | Order Picker |
| 535 | Order Planner |
| 536 | Order Processing Clerk |
| 537 | Order Processing Specialist |
| 538 | Order Processor |
| 539 | Order Runner |
| 540 | Order Schedule Clerk |
| 541 | Order Selector |
| 542 | Order Specialist |
| 543 | Order Taker |
| 544 | Order Takers Supervisor |
| 545 | Order to Delivery Supervisor |
| 546 | Order Tracer |
| 547 | Order Worker |
| 548 | Ordering Machine Operator |
| 549 | Orderlies |
| 550 | Orderly |
| 551 | Ordinary Seaman |
| 552 | Ordnance Artificer |
| 553 | Ordnance Artificer Helper |
| 554 | Ordnance Equipment Worker |
| 555 | Ordnance Handler |
| 556 | Ordnance Keeper |
| 557 | Ordnance Truck Installation Mechanic |
| 558 | Ordnance Truck Installation Supervisor |
| 559 | Ore Blasting Miner |
| 560 | Ore Bridge Operator |
| 561 | Ore Buyer |
| 562 | Ore Charger |
| 563 | Ore Crusher |
| 564 | Ore Digger |
| 565 | Ore Dressing Engineer |
| 566 | Ore Dryer |
| 567 | Ore Grader |
| 568 | Ore Mixer |
| 569 | Ore Puncher |
| 570 | Ore Roaster |
| 571 | Ore Sampler |
| 572 | Ore Smelter |
| 573 | Ore Storage Drier |
| 574 | Ore Tester |
| 575 | Ore Trimmer |
| 576 | Ore Washer |
| 577 | Organ Console Assembler |
| 578 | Organ Fixer |
| 579 | Organ Installer |
| 580 | Organ Pipe Voicer |
| 581 | Organ Preservationist |
| 582 | Organ Teacher |
| 583 | Organ Tuner |
| 584 | Organic Chemist |
| 585 | Organic Chemistry Instructor |
| 586 | Organic Chemistry Professor |
| 587 | Organic Chemistry Teacher |
| 588 | Organic Preparation Analyst (Organic Prep Analyst) |
| 589 | Organic Preparation Technician (Organic Prep Technician) |
| 590 | Organist |
| 591 | Organizational Change Manager |
| 592 | Organizational Consultant |
| 593 | Organizational Development Consultant |
| 594 | Organizational Development Consultant (OD Consultant) |
| 595 | Organizational Development Specialist (OD Specialist) |
| 596 | Organizational Investment Analyst |
| 597 | Organizational Psychologist |
| 598 | Organizational Research Consultant |
| 599 | Oriental Medicine Provider |
| 600 | Oriental Rug Stretcher |
| 601 | Orientation and Mobility Instructor (O and M Instructor) |
| 602 | Orientation and Mobility Specialist (O and M Specialist) |
| 603 | Orientation Specialist |
| 604 | Origination Director |
| 605 | Origination Specialist |
| 606 | Ornament Stitcher |
| 607 | Ornamental Iron Erector |
| 608 | Ornamental Ironworker |
| 609 | Ornamental Ironworking Supervisor |
| 610 | Ornamental Machine Operator |
| 611 | Ornamental Metal Erector |
| 612 | Ornamental Metal Worker |
| 613 | Ornamental Metal Worker Helper |
| 614 | Ornamental Metalwork Designer |
| 615 | Ornamental Painter |
| 616 | Ornamental Plasterer |
| 617 | Ornamental Plasterer Helper |
| 618 | Ornamenter |
| 619 | Ornithologist |
| 620 | Ornithology Teacher |
| 621 | Orthodontic Assistant (Ortho Assistant) |
| 622 | Orthodontic Band Maker (Ortho Band Maker) |
| 623 | Orthodontic Laboratory Technician (Ortho Lab Tech) |
| 624 | Orthodontic Technician (Ortho Tech) |
| 625 | Orthodontics and Dentofacial Orthopedics Specialist |
| 626 | Orthodontist |
| 627 | Orthodontist Assistant |
| 628 | Orthodontists |
| 629 | Orthopaedic Physician Assistant |
| 630 | Orthopaedic Surgeon |
| 631 | Orthopaedic Technician |
| 632 | Orthopaedic Technologist |
| 633 | Orthopedic Assistant |
| 634 | Orthopedic Boot and Shoe Designer |
| 635 | Orthopedic Boot and Shoe Maker |
| 636 | Orthopedic Brace Maker |
| 637 | Orthopedic Designer |
| 638 | Orthopedic Manufacturing Technologist |
| 639 | Orthopedic Mechanic |
| 640 | Orthopedic Nurse Practitioner |
| 641 | Orthopedic Physical Therapist (Orthopedic PT) |
| 642 | Orthopedic Physician Assistant |
| 643 | Orthopedic Podiatrist |
| 644 | Orthopedic Shoe Fitter |
| 645 | Orthopedic Shoe Maker |
| 646 | Orthopedic Shoes Salesperson |
| 647 | Orthopedic Surgeon |
| 648 | Orthopedic Surgeons, Except Pediatric |
| 649 | Orthopedic Team Physician |
| 650 | Orthopedic Technician |
| 651 | Orthopedics Teacher |
| 652 | Orthophotography Technician |
| 653 | Orthoptist |
| 654 | Orthoptists |
| 655 | Orthotic and Prosthetic Technician (O and P Technician) |
| 656 | Orthotic Clinician |
| 657 | Orthotic Fabricator Technician |
| 658 | Orthotic Finish Grinding Technician |
| 659 | Orthotic Fitter |
| 660 | Orthotic Practitioner |
| 661 | Orthotic Prosthetic Technician (Orthotic Prosthetic Tech) |
| 662 | Orthotic Technician |
| 663 | Orthotics Fitter |
| 664 | Orthotics Technician |
| 665 | Orthotist |
| 666 | Orthotists and Prosthetists |
| 667 | OSHA Inspector (Occupational Safety and Health Administration Inspector) |
| 668 | Osteology Teacher |
| 669 | Osteopathic Medicine Teacher |
| 670 | Osteopathic Neurologist |
| 671 | OTC Clerk (Over the Counter Clerk) |
| 672 | Otolaryngology Teacher |
| 673 | OTR Truck Driver (Over the Road Truck Driver) |
| 674 | Outboard Motor Inspector |
| 675 | Outboard Motor Mechanic |
| 676 | Outboard Motor Tester |
| 677 | Outboard Motorboat Operator |
| 678 | Outboard Motors Experimental Mechanic |
| 679 | Outboard Technician |
| 680 | Outbound Operator |
| 681 | Outbound Supervisor |
| 682 | Outbound Telemarketer |
| 683 | Outdoor Advertising Leasing Agent |
| 684 | Outdoor Guide |
| 685 | Outdoor Landscape Architect |
| 686 | Outdoor Power Equipment and Other Small Engine Mechanics |
| 687 | Outdoor Power Equipment Mechanic (OPE Mechanic) |
| 688 | Outdoor Power Equipment Service Technician |
| 689 | Outer Diameter Grinder (OD Grinder) |
| 690 | Outer Diameter Technician (OD Technician) |
| 691 | Outfitter |
| 692 | Outpatient Admitting Clerk |
| 693 | Outpatient Aide |
| 694 | Outpatient Clerk |
| 695 | Outpatient Clinician |
| 696 | Outpatient Counselor |
| 697 | Outpatient Dietitian |
| 698 | Outpatient Interviewing Clerk |
| 699 | Outpatient Phlebotomist |
| 700 | Outpatient Physical Therapist (Outpatient PT) |
| 701 | Outpatient Physical Therapist Assistant |
| 702 | Outpatient Psychiatrist |
| 703 | Outpatient Services Director |
| 704 | Outpatient Surgery Assistant |
| 705 | Outpatient Therapist |
| 706 | Outpatient Therapy Aide |
| 707 | Outplacement Consultant |
| 708 | Outreach Coordinator |
| 709 | Outreach Librarian |
| 710 | Outrider |
| 711 | Outside Barrel Lathe Operator |
| 712 | Outside Cutter |
| 713 | Outside Deliverer |
| 714 | Outside Food Server |
| 715 | Outside Machinist |
| 716 | Outside Machinist Supervisor |
| 717 | Outside Maintenance Worker |
| 718 | Outside Operator |
| 719 | Outside Physical Damage Appraiser |
| 720 | Outside Plant Cable Engineer |
| 721 | Outside Plant Engineer |
| 722 | Outside Plant Technician |
| 723 | Outside Production Inspector |
| 724 | Outside Property Agent |
| 725 | Outside Rigger |
| 726 | Outside Sales Representative |
| 727 | Outsole Caser |
| 728 | Outsole Cementer |
| 729 | Outsole Compressor |
| 730 | Outsole Flexer |
| 731 | Outsole Handler |
| 732 | Outsole Rounder |
| 733 | Outsole Scheduler |
| 734 | Outsole Splicer |
| 735 | Oven Baker |
| 736 | Oven Builder |
| 737 | Oven Dauber |
| 738 | Oven Dumper |
| 739 | Oven Equipment Repairer |
| 740 | Oven Heater |
| 741 | Oven Heater Helper |
| 742 | Oven Loader |
| 743 | Oven Operator |
| 744 | Oven Press Tender |
| 745 | Oven Technician |
| 746 | Oven Tender |
| 747 | Oven Worker |
| 748 | Ovens Supervisor |
| 749 | Over Hauler Helper |
| 750 | Over the Road Driver (OTR Driver) |
| 751 | Overcaster |
| 752 | Overedge Machine Operator |
| 753 | Overedge Sewer |
| 754 | Overedger |
| 755 | Overhauler |
| 756 | Overhauler Helper |
| 757 | Overhead Cleaner Maintainer |
| 758 | Overhead Crane Operator |
| 759 | Overhead Crane Truck Loader |
| 760 | Overhead Door Installer |
| 761 | Overhead Door Technician |
| 762 | Overhead Garage Door Hanger |
| 763 | Overhead Irrigator |
| 764 | Overhead Line Worker |
| 765 | Overhead Worker |
| 766 | Overlock Collar Setter |
| 767 | Overlock Elastic Attacher |
| 768 | Overlock Hemmer |
| 769 | Overlock Operator |
| 770 | Overlock Sewing Machine Operator |
| 771 | Overlock Sleeve Setter |
| 772 | Overlock Waistline Joiner |
| 773 | Overlocker |
| 774 | Overnight Associate |
| 775 | Overseamer |
| 776 | Oxidation Engineer |
| 777 | Oxidation Operator |
| 778 | Oxide Furnace Tender |
| 779 | Oxidized Finish Plater |
| 780 | Oxidizer |
| 781 | Oxyacetylene Burner |
| 782 | Oxyacetylene Cutter |
| 783 | Oxyacetylene Torch Operator |
| 784 | Oxyacetylene Welder |
| 785 | Oxygen Equipment Preparer |
| 786 | Oxygen Furnace Operator |
| 787 | Oxygen Plant Operator |
| 788 | Oxygen System Tester |
| 789 | Oxygen Tank Filler |
| 790 | Oxygen Therapist |
| 791 | Oxygen Therapy Teacher |
| 792 | Oxygraph Operator |
| 793 | Oxyhydrogen Welder |
| 794 | Oyster Buyer |
| 795 | Oyster Farmer |
| 796 | Oyster Farmworker |
| 797 | Oyster Grader |
| 798 | Oyster Opener |
| 799 | Oyster Picker |
| 800 | Oyster Shipper |
| 801 | Oyster Shucker |
| 802 | Oyster Sorter |
| 803 | Oyster Washer |
