| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| OCA (OCEAN REEF CLUB) | airport | United States | 25.33 | -80.27 | 8 | 0 | |
| OCALA INTL JIM TAYLOR FLD | airport | United States | 29.17 | -82.22 | 89 | 0 | |
| OCANA | airport | Spain | 39.94 | -3.50 | 2405 | 0 | |
| OCC (FRANCISCO DE ORELLANA) | airport | Ecuador | -0.46 | -76.99 | 834 | 0 | |
| OCCIDENTAL PETROLEUM | airport | United States | 34.06 | -118.44 | 509 | 0 | |
| OCE (OCEAN CITY MUNI) | airport | United States | 38.31 | -75.12 | 11 | 0 | |
| OCEAN BEACH HOSPITAL | airport | United States | 46.30 | -124.04 | 25 | 0 | |
| OCEAN CITY MUNI | airport | United States | 39.26 | -74.61 | 5 | 0 | |
| OCEAN CITY MUNI | airport | United States | 38.31 | -75.12 | 11 | 0 | |
| OCEAN REEF CLUB | airport | United States | 25.33 | -80.27 | 8 | 0 | |
| OCEAN RIDGE | airport | United States | 38.80 | -123.53 | 940 | 0 | |
| OCEAN SHORES MUNI | airport | United States | 47.00 | -124.14 | 13 | 0 | |
| OCEAN SPRINGS | airport | United States | 30.39 | -88.75 | 20 | 0 | |
| OCEANA CO | airport | United States | 43.64 | -86.33 | 910 | 0 | |
| OCEANA NAS | airport | United States | 36.82 | -76.03 | 22 | 0 | |
| OCEANO COUNTY | airport | United States | 35.10 | -120.62 | 14 | 0 | |
| OCEANSIDE MUNI | airport | United States | 33.22 | -117.35 | 28 | 0 | |
| OCF (OCALA INTL JIM TAYLOR FLD) | airport | United States | 29.17 | -82.22 | 89 | 0 | |
| OCHEY | airport | France | 48.58 | 5.96 | 1106 | 0 | |
| OCHS PRIVATE | airport | United States | 44.78 | -120.96 | 1790 | 0 | |
| OCHSNER | airport | United States | 41.84 | -97.42 | 1630 | 0 | |
| OCHSNER MEDICAL INSTITUTIONS | airport | United States | 29.97 | -90.14 | 7 | 0 | |
| OCHSNER ST ANNE GENERAL HOSPITAL | airport | United States | 29.70 | -90.57 | 11 | 0 | |
| OCJ (BOSCOBEL) | airport | Jamaica | 18.40 | -76.97 | 90 | 0 | |
| OCKEL FARMS | airport | United States | 38.75 | -75.36 | 47 | 0 | |
| OCM (Boolgeeda) | airport | -22.54 | 117.28 | 1871 | 0 | ||
| OCN (OCEANSIDE MUNI) | airport | United States | 33.22 | -117.35 | 28 | 0 | |
| OCONEE CO RGNL | airport | United States | 34.67 | -82.89 | 892 | 0 | |
| OCONOMOWOC | airport | United States | 43.14 | -88.47 | 885 | 0 | |
| OCOTILLO | airport | United States | 33.15 | -116.13 | 160 | 0 | |
| OCRACOKE ISLAND | airport | United States | 35.10 | -75.97 | 5 | 0 | |
| OCS (Corisco International Airport) | airport | 0.91 | 9.33 | 55 | 0 | ||
| OCSENY | airport | Hungary | 46.30 | 18.77 | 295 | 0 | |
| OCTEVILLE | airport | France | 49.53 | 0.09 | 312 | 0 | |
| OCTOBER | airport | Egypt | 29.81 | 30.82 | 807 | 0 | |
| OCV (AGUAS CLARAS) | airport | Colombia | 8.32 | -73.36 | 3850 | 0 |