C
- (Madison County) Conclusion Island
- (Prince of Wales-Hyder Census Area) Comma Island
- (Perry County) Composite Island
- (Ketchikan Gateway Borough) Cone Island
- (Prince of Wales-Hyder Census Area) Cone Island
- (Madison County) Coney Island
- (Ketchikan Gateway Borough) Coon Island
- (Sitka City and Borough) Cormorant Island
- (Madison County) Cora Island
- (Prince of Wales-Hyder Census Area) Cristina Island
- (Thomas County) Cottonwood Island
- (Thomas County) Cottonwood Islands
- (Haines Borough) Couverden Island
- (Ketchikan Gateway Borough) Cow Island
- (Prince of Wales-Hyder Census Area) Craig Island
- (Sitka City and Borough) Crosswise Islands
- (Prince of Wales-Hyder Census Area) Cruz Islands
- (Perry County) Crow Island
- (Prince of Wales-Hyder Census Area) Crow Island
- (Sitka City and Borough) Crow Island
- (Prince of Wales-Hyder Census Area) Culebrina Island
- (Prince of Wales-Hyder Census Area) Culebra Islands
- (Ketchikan Gateway Borough) Cygnet Island
- (Ketchikan Gateway Borough) Cynthia Island
- (Sitka City and Borough) Crow Island
- (Yakutat City and Borough) Crab Island
- (Haines Borough) Couverden Rock
- (Madison County) Coronation Island
- (Prince of Wales-Hyder Census Area) Corlies Islands
- (Prince of Wales-Hyder Census Area) Coposo Island