Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| O'Neill Post Office | Post Office | 610 | Holt | 42 27 33 N | 098 38 53 W |
| Oak | Populated Place | 484 | Nuckolls | 40 14 13 N | 097 54 12 W |
| Oak (historical) | Locale | 485 | Nuckolls | 40 14 15 N | 097 54 21 W |
| Oak Ballroom | Building | 412 | Colfax | 41 26 15 N | 097 03 39 W |
| Oak Bowl Athletic Field | Building | 298 | Nemaha | 40 28 30 N | 095 43 46 W |
| Oak Cemetery | Cemetery | 488 | Nuckolls | 40 13 57 N | 097 52 25 W |
| Oak Creek | Stream | | Holt | 42 41 08 N | 098 44 33 W |
| Oak Creek | Stream | | Keya Paha | 42 54 17 N | 099 15 09 W |
| Oak Creek | Stream | | Nuckolls | 40 01 04 N | 098 02 37 W |
| Oak Creek | Stream | 481 | Nuckolls | 40 01 50 N | 098 11 28 W |
| Oak Creek | Stream | | Nuckolls | 40 13 41 N | 097 53 23 W |
| Oak Creek | Stream | | Rock | 42 46 39 N | 099 20 41 W |
| Oak Creek | Stream | | Seward | 40 50 12 N | 096 41 51 W |
| Oak Creek | Stream | | Sherman | 41 08 28 N | 099 08 40 W |
| Oak Creek | Stream | | Valley | 41 07 01 N | 098 31 49 W |
| Oak Creek | Stream | | Webster | 40 02 11 N | 098 25 03 W |
| Oak Creek | Stream | | Webster | 40 24 39 N | 098 16 14 W |
| Oak Creek | Stream | | Webster | 40 23 24 N | 098 13 09 W |
| Oak Creek Area Campground | Locale | 671 | Sherman | 41 21 28 N | 098 56 11 W |
| Oak Creek Cemetery | Cemetery | 387 | Lancaster | 40 56 44 N | 096 46 00 W |
| Oak Creek Cemetery | Cemetery | 580 | Webster | 40 20 37 N | 098 19 47 W |
| Oak Creek Park | Park | 342 | Lancaster | 40 50 00 N | 096 42 51 W |
| Oak Creek School (historical) | School | 672 | Sherman | 41 06 17 N | 099 08 25 W |
| Oak Election Precinct | Civil | 409 | Lancaster | 40 55 13 N | 096 44 21 W |
| Oak Glen State Wildlife Management Area | Park | 444 | Seward | 40 58 30 N | 096 59 11 W |
| Oak Grove Campground | Locale | 339 | Douglas | 41 13 34 N | 096 21 14 W |
| Oak Grove Cemetery | Cemetery | 411 | Saline | 40 24 18 N | 096 56 55 W |
| Oak Grove Cemetery | Cemetery | 434 | Seward | 40 59 41 N | 096 56 18 W |
| Oak Grove Manor | Hospital | 349 | Douglas | 41 18 35 N | 095 59 11 W |
| Oak Heights Park | Park | 331 | Douglas | 41 14 37 N | 096 04 31 W |
| Oak Hill Cemetery | Cemetery | 362 | Cass | 41 00 38 N | 095 54 46 W |
| Oak Hill Family Housing | Building | 310 | Nemaha | 40 28 30 N | 095 43 41 W |
| Oak Hills Country Club | Locale | 317 | Douglas | 41 11 30 N | 096 06 06 W |
| Oak Lake | Reservoir | 355 | Lancaster | 40 49 55 N | 096 42 42 W |
| Oak Lake Evangelical Free Church | Church | 360 | Lancaster | 40 50 42 N | 096 43 11 W |
| Oak Middle Creek Reservoir 63-D | Reservoir | 460 | Butler | 41 06 36 N | 096 59 19 W |
| Oak Middle Reservoir 68-A | Reservoir | 456 | Butler | 41 05 18 N | 096 59 55 W |
| Oak Middle Reservoir 72-A | Reservoir | 405 | Seward | 40 58 12 N | 096 56 01 W |
| Oak Middle Reservoir 87-A | Reservoir | 442 | Seward | 41 01 24 N | 097 00 37 W |
| Oak Mill | Populated Place | 476 | Nuckolls | 40 13 33 N | 097 52 33 W |
| Oak Park | Park | 729 | Dawson | 40 46 07 N | 099 44 41 W |
| Oak Park | Park | 321 | Douglas | 41 12 25 N | 096 02 05 W |
| Oak Post Office | Post Office | 484 | Nuckolls | 40 14 13 N | 097 54 12 W |
| Oak Reservoir 58-B | Reservoir | 413 | Seward | 41 01 30 N | 096 56 25 W |
| Oak Ridge Cemetery | Cemetery | 569 | Howard | 41 06 50 N | 098 32 56 W |
| Oak Valley | Valley | | Webster | 40 03 07 N | 098 22 21 W |
| Oak Valley Elementary School | School | 349 | Douglas | 41 13 44 N | 096 06 28 W |
| Oak Valley Public School | School | 360 | Lancaster | 40 54 05 N | 096 45 47 W |
| Oak Valley School | School | 438 | Knox | 42 31 57 N | 098 05 39 W |
| Oak Valley School | School | 501 | Knox | 42 33 26 N | 098 13 40 W |
| Oak Valley State Wildlife Management Area | Park | 518 | Madison | 41 57 00 N | 097 37 01 W |
| Oak View Mall | Locale | 341 | Douglas | 41 13 58 N | 096 08 16 W |
| Oak Volunteer Fire Department | Building | 484 | Nuckolls | 40 14 13 N | 097 54 12 W |
| Oak-Middle Reservoir 63-C | Reservoir | 440 | Butler | 41 05 54 N | 096 57 13 W |
| Oak-Middle Reservoir 76-A | Reservoir | 413 | Seward | 40 58 48 N | 096 57 01 W |
| Oak-Middle Reservoir 79-A | Reservoir | 432 | Seward | 41 00 36 N | 096 58 13 W |
| Oak-Middle Reservoir 81-A | Reservoir | 429 | Seward | 40 59 24 N | 096 58 49 W |
| Oak-Middle Reservoir 82-B | Reservoir | 451 | Seward | 41 01 00 N | 097 00 43 W |
| Oak-Middle Reservoir 84-A | Reservoir | 454 | Seward | 41 02 06 N | 096 59 43 W |
| Oak-Middle Reservoir 86-A | Reservoir | 452 | Seward | 41 02 00 N | 097 00 37 W |
| Oakbrook Park | Park | 320 | Douglas | 41 16 25 N | 096 05 11 W |
| Oakdale | Populated Place | 523 | Antelope | 42 04 11 N | 097 58 09 W |
| Oakdale (historical) | Locale | 519 | Antelope | 42 04 19 N | 097 57 51 W |
| Oakdale Cemetery | Cemetery | 562 | Antelope | 42 03 14 N | 097 58 21 W |
| Oakdale Cemetery | Cemetery | 583 | Boyd | 42 53 05 N | 099 11 39 W |
| Oakdale City Park | Park | 522 | Antelope | 42 04 15 N | 097 58 11 W |
| Oakdale Elementary School (historical) | School | 525 | Antelope | 42 04 02 N | 097 58 08 W |
| Oakdale Fire Department | Building | 523 | Antelope | 42 04 09 N | 097 58 08 W |
| Oakdale Post Office | Post Office | 523 | Antelope | 42 04 10 N | 097 58 11 W |
| Oakdale Public Library | Building | 523 | Antelope | 42 04 11 N | 097 58 09 W |
| Oakdale School | School | 345 | Douglas | 41 13 60 N | 096 03 54 W |
| Oakdale Seventh Day Adventist Elementary School | School | 521 | Antelope | 42 04 08 N | 097 57 36 W |
| Oakland | Locale | 394 | Burt | 41 50 05 N | 096 28 03 W |
| Oakland | Populated Place | 395 | Burt | 41 50 09 N | 096 28 01 W |
| Oakland City Park | Park | 379 | Burt | 41 49 55 N | 096 28 41 W |
| Oakland City Park Campground | Locale | 379 | Burt | 41 49 55 N | 096 28 41 W |
| Oakland Craig Elementary School | School | 395 | Burt | 41 50 09 N | 096 28 01 W |
| Oakland Craig Senior High | School | 411 | Burt | 41 50 11 N | 096 27 49 W |
| Oakland Election Precinct | Civil | 607 | Boone | 41 52 00 N | 098 09 06 W |
| Oakland Family Practice | Hospital | 400 | Burt | 41 50 07 N | 096 27 58 W |
| Oakland Fire Hall | Building | 391 | Burt | 41 50 17 N | 096 28 01 W |
| Oakland Golf Club | Locale | 380 | Burt | 41 50 03 N | 096 28 31 W |
| Oakland Heights | Hospital | 406 | Burt | 41 49 55 N | 096 27 26 W |
| Oakland Medical Clinic | Hospital | 402 | Burt | 41 50 05 N | 096 27 33 W |
| Oakland Memorial Hospital | Hospital | 402 | Burt | 41 50 05 N | 096 27 33 W |
| Oakland Post Office | Post Office | 396 | Burt | 41 50 10 N | 096 27 59 W |
| Oakland Public Library | Building | 399 | Burt | 41 50 08 N | 096 27 57 W |
| Oaks Park | Park | 340 | Douglas | 41 12 43 N | 096 06 41 W |
| Oatman Ranch | Locale | 835 | Brown | 42 21 44 N | 100 07 27 W |
| OB-GYN Group Building | Building | 349 | Douglas | 41 15 56 N | 096 02 53 W |
| Obert | Populated Place | 410 | Cedar | 42 41 23 N | 097 01 41 W |
| Obert Cemetery | Cemetery | 434 | Cedar | 42 40 13 N | 097 01 45 W |
| Obert Park | Park | 410 | Cedar | 42 41 23 N | 097 01 41 W |
| Obert Park Campground | Locale | 410 | Cedar | 42 41 23 N | 097 01 41 W |
| Obert Post Office | Post Office | 410 | Cedar | 42 41 23 N | 097 01 41 W |
| Observatory | Locale | 583 | Adams | 40 35 43 N | 098 22 09 W |
| Ochsner Grain Company Incorporated Elevator | Locale | 484 | Madison | 41 49 42 N | 097 27 18 W |
| Ochsner Heliport | Airport | 500 | Madison | 41 50 37 N | 097 25 02 W |
| Ockinga Center | Building | 668 | Buffalo | 40 42 06 N | 099 06 21 W |
| Oconee | Locale | 454 | Platte | 41 28 12 N | 097 31 08 W |
| Oconee | Populated Place | 454 | Platte | 41 28 12 N | 097 31 08 W |
| Oconee Post Office (historical) | Post Office | 454 | Platte | 41 28 12 N | 097 31 08 W |
| Oconto | Populated Place | 784 | Custer | 41 08 28 N | 099 45 47 W |
| Oconto City Park | Park | 784 | Custer | 41 08 32 N | 099 45 46 W |
| Oconto Fire Hall | Building | 784 | Custer | 41 08 30 N | 099 45 48 W |
| Oconto Library | Building | 784 | Custer | 41 08 32 N | 099 45 49 W |
| Oconto Post Office | Post Office | 784 | Custer | 41 08 28 N | 099 45 47 W |
| Oconto Public School | School | 783 | Custer | 41 08 23 N | 099 45 35 W |
| Octavia | Populated Place | 430 | Butler | 41 20 53 N | 097 03 32 W |
| Octavia (historical) | Locale | 429 | Butler | 41 20 56 N | 097 03 33 W |