Trinity Island may refer to:
- Trinity Island, Palmer Archipelago, Antarctica
- Trinity Island, Willis Islands, South Georgia
- Trinity Islands (Nunavut), an uninhabited island group offshore Baffin Island, belonging to the Canadian territory of Nunavut
- Trinity Islands (Alaska), an uninhabited island group consisting of the two larger islands Sitkinak and Tugidak, as well as several smaller islands, lying off Kodiak Island and belonging to Kodiak Island Borough in the U.S. state of Alaska
- Trinity Islands, Manchester, a proposed skyscraper development in Manchester, England.