O
- Old Tyonek
- Old Cutoff Trading Post
- Omilak
- (Yukon-Koyukuk Census Area) Old Rampart
- Old Camp
- (Bethel Census Area) Oronikowaktalik Rock
- (Yukon-Koyukuk Census Area) Oscar Island
- (Fairbanks North Star Borough) Olnes
- (Aleutians West Census Area) Otter Island
- (Campbell County) Outer Iliasik Island
- (Kenai Peninsula Borough) Outer Island
- (Aleutians West Census Area) Outer Rock
- (Kodiak Island Borough) Outer Seal Rock
- (Aleutians West Census Area) Outer Signal
- (Sumter County) Outpost Island
- Old Saulich
- (Campbell County) Olga Islands
- Okok Point
- (Kodiak Island Borough) Onion Bay
- (Sitka City and Borough) O'Neil Island
- Old Andreafsky
- (Bethel Census Area) Oskawalik
- Otter
- Oregon
- (Kusilvak Census Area) Ohogamiut
- (Yukon-Koyukuk Census Area) Ophir
- (Greene County) Orca
- (Yukon-Koyukuk Census Area) Old Minto
- (Campbell County) Omega Island
- (Aleutians West Census Area) Outer Rock