Garretty Island is an island in Mulligan Bay, Georgeland. It forms part of the city of Santa Christina, of which it is one of ten boroughs. Garretty Island is highly urbanised with a high population density. Its population in 2007 was 108,598.
Garretty Island is known as the home of the Garretty Island Science Centre, a world-renowned museum of science and technology.
The island is named for George Garretty, a former Mayor of Santa Christina. Prior to its renaming in Garretty's honour in 1977, the island was known as Fortune Island.
As a civic borough of the city of Santa Christina, Garretty Island elects three members to the Santa Christina City Council. The Borough Council is an elected body which advises the city council and has limited jurisdiction over the island in some areas. The Borough Council is headed by a President - the incumbent President is Laura Wong of the Liberal Democratic Party.