- Olsen Island
- Omega Island
- Omilak
- Onetree Rock
- Onion Bay
- Onslow Island
- Operl Island
- Ophir
- Orca
- Oregon
- Oronikowaktalik Rock
- Orr Island
- Oscar Island
- Osier Island
- Oskawalik
- Osten Island
- Otmeloi Island
- Otstoia Island
- Otter
- Otter Island
- Outer Iliasik Island
- Outer Island
- Outer Rock
- Outer Rock
- Outer Seal Rock
- Outer Signal
- Outpost Island
- Oval Rock
- Owl Island
- Old Harbor