| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| OLAFSON BROTHERS | airport | United States | 48.63 | -97.83 | 1045 | 0 | |
| OLCOTT-NEWFANE | airport | United States | 43.32 | -78.73 | 315 | 0 | |
| OLD (DEWITT FLD OLD TOWN MUNI) | airport | United States | 44.95 | -68.67 | 126 | 0 | |
| OLD 66 STRIP | airport | United States | 36.83 | -94.90 | 853 | 0 | |
| OLD ACTON AIRFIELD | airport | United States | 43.54 | -70.93 | 700 | 0 | |
| OLD AERODROME | airport | United States | 39.32 | -121.36 | 700 | 0 | |
| OLD BRIDGE | airport | United States | 40.33 | -74.35 | 87 | 0 | |
| OLD DAIRY | airport | United States | 46.69 | -90.87 | 725 | 0 | |
| OLD FORGE | airport | United States | 43.73 | -74.98 | 1753 | 0 | |
| OLD FORKER | airport | United States | 29.32 | -95.09 | 15 | 0 | |
| OLD FORT FARM | airport | United States | 42.81 | -77.57 | 1050 | 0 | |
| OLD HARBOR | airport | United States | 57.22 | -153.27 | 55 | 0 | |
| OLD HICKORY RANCH | airport | United States | 32.35 | -93.82 | 180 | 0 | |
| OLD HOPPE PLACE | airport | United States | 27.80 | -97.85 | 96 | 0 | |
| OLD KINGSBURY AERODROME | airport | United States | 29.63 | -97.81 | 560 | 0 | |
| OLD ORCHARD | airport | United States | 41.01 | -78.56 | 1980 | 0 | |
| OLD ORCHARD AIRPARK | airport | United States | 41.66 | -74.08 | 660 | 0 | |
| OLD ORCHARD ROAD | airport | United States | 41.11 | -73.72 | 527 | 0 | |
| OLD PLAINS | airport | United States | 40.39 | -75.44 | 660 | 0 | |
| OLD PORT ROYAL | airport | United States | 42.11 | -77.09 | 1700 | 0 | |
| OLD PORTAGE | airport | United States | 41.14 | -81.55 | 760 | 0 | |
| OLD REB | airport | United States | 26.18 | -97.88 | 60 | 0 | |
| OLD RHINEBECK | airport | United States | 41.97 | -73.86 | 323 | 0 | |
| OLD SAYBROOK | airport | United States | 41.30 | -72.37 | 100 | 0 | |
| OLD SAYBROOK POLICE | airport | United States | 41.29 | -72.38 | 16 | 0 | |
| OLD SOUTH AERODROME | airport | United States | 36.68 | -81.93 | 1970 | 0 | |
| OLD TOWN EMS | airport | United States | 29.60 | -82.98 | 25 | 0 | |
| OLDFIELD AERO | airport | United States | 40.75 | -92.03 | 750 | 0 | |
| OLDHAM CO | airport | United States | 35.23 | -102.40 | 3995 | 0 | |
| OLE (CATTARAUGUS CO OLEAN) | airport | United States | 42.24 | -78.37 | 2135 | 0 | |
| OLEAN GENERAL | airport | United States | 42.09 | -78.43 | 1426 | 0 | |
| OLEO | airport | United States | 39.74 | -86.73 | 870 | 0 | |
| OLF (L M CLAYTON) | airport | United States | 48.09 | -105.58 | 1986 | 0 | |
| OLFERT | airport | United States | 48.40 | -106.01 | 2750 | 0 | |
| OLGA BAY | airport | United States | 57.16 | -154.23 | 0 | 0 | |
| OLH (OLD HARBOR) | airport | United States | 57.22 | -153.27 | 55 | 0 | |
| OLINGER AIRPARK | airport | United States | 45.56 | -123.02 | 185 | 0 | |
| OLIVE BRANCH | airport | United States | 34.98 | -89.79 | 402 | 0 | |
| OLIVE HILL-SELLERS' FIELD | airport | United States | 38.25 | -83.14 | 1016 | 0 | |
| OLIVE VIEW MEDICAL CENTER | airport | United States | 34.33 | -118.44 | 1460 | 0 | |
| OLIVER | airport | United States | 33.42 | -99.87 | 1500 | 0 | |
| OLIVER LAKE | airport | United States | 41.57 | -85.41 | 900 | 0 | |
| OLIVER LANDING | airport | United States | 36.41 | -88.27 | 475 | 0 | |
| OLIVER SPRINGS INC | airport | United States | 36.04 | -84.31 | 790 | 0 | |
| OLIVERS | airport | United States | 42.10 | -88.37 | 895 | 0 | |
| OLIVIA RGNL | airport | United States | 44.78 | -95.03 | 1076 | 0 | |
| OLJATO | airport | United States | 37.03 | -110.32 | 4838 | 0 | |
| OLLA | airport | United States | 31.90 | -92.22 | 130 | 0 | |
| OLLER | airport | United States | 43.88 | -100.36 | 2100 | 0 | |
| OLM (OLYMPIA) | airport | United States | 46.97 | -122.90 | 209 | 0 | |
| OLMSTEAD LANDING STRIP | airport | United States | 42.27 | -75.31 | 1160 | 0 | |
| OLMSTEAD SKY RANCH | airport | United States | 48.35 | -116.55 | 2140 | 0 | |
| OLNEY MUNI | airport | United States | 33.35 | -98.82 | 1275 | 0 | |
| OLNEY NOBLE | airport | United States | 38.72 | -88.18 | 482 | 0 | |
| OLS (NOGALES INTL) | airport | United States | 31.42 | -110.85 | 3955 | 0 | |
| OLSON | airport | United States | 42.35 | -89.29 | 750 | 0 | |
| OLSON | airport | United States | 42.01 | -88.46 | 955 | 0 | |
| OLSON | airport | United States | 47.59 | -114.05 | 3330 | 0 | |
| OLSON AERODROME | airport | United States | 37.52 | -97.20 | 1325 | 0 | |
| OLSON FIELD | airport | United States | 40.57 | -99.42 | 2330 | 0 | |
| OLSON'S | airport | United States | 42.66 | -88.09 | 825 | 0 | |
| OLTMAN-SHUCK | airport | United States | 40.89 | -89.10 | 736 | 0 | |
| OLU (COLUMBUS MUNI) | airport | United States | 41.45 | -97.34 | 1444 | 0 | |
| OLUSTEE MUNI | airport | United States | 34.51 | -99.43 | 1346 | 0 | |
| OLV (OLIVE BRANCH) | airport | United States | 34.98 | -89.79 | 402 | 0 | |
| OLYMPIA | airport | United States | 46.96 | -122.89 | 200 | 0 | |
| OLYMPIA | airport | United States | 46.97 | -122.90 | 209 | 0 | |
| OLYMPIC FIELD | airport | United States | 48.00 | -122.90 | 500 | 0 | |
| OLYMPIC MEMORIAL HOSPITAL | airport | United States | 48.12 | -123.40 | 96 | 0 |