- Oyle Island
- O'Neil Island
- Oarlock Island
- Obsechki Island
- Observation Island
- Observation Island
- Observation Rock
- Ogangen Island
- Ogchul Island
- Ogliuga Island
- Oglodak Island
- Ohogamiut
- Okok Point
- Old Andreafsky
- Old Camp
- Old Cutoff Trading Post
- Old Harbor
- Old Iliamna
- Old Kotzebue
- Old Man Rocks
- Old McGrath
- Old Minto
- Old Rampart
- Old Salmon Village
- Old Saulich
- Old Tyonek
- Old Valdez
- Olga Islands
- Olga Rock
- Olnes