Happiness Island is officially classed as part of the borough of Algonquin, and is the city's southernmost point. It is based on Liberty Island, complete with its own version of the Statue of Liberty, called the Statue of Happiness. Niko will kill either Dimitri Rascalov or Jimmy Pegorino on Happiness Island, depending on the ending the player chooses.
Unlike Liberty Island, Happiness Island has only a light police presence. If the player gains a wanted level, no reinforcements will arrive (apart from Police Mavericks and Annihilators), as the island is isolated from the mainland, and Predator patrol-boats cannot dock to transport foot police. The island is large enough for the player to escape from a two (in some cases three) Wanted Level search radius on foot if they stay out of sight of police, which is useful for players hunting the six pigeons on the island, though there are several officers at the dock at throughout the island with M4 Carbine rifles/9mms. In TBoGT, there will also be two police officers near the entrance to the "building" under the Statue of Happiness.
The "Happiness Is...Land" Sweater can be found on Happiness Island.
According to radio news reports, a beached whale washed up on the Island in 2007.
- In Grand Theft Auto: Chinatown Wars, there are no vehicles on Happiness Island, and no normal way to transport them across. However, there are two bugs the player can exploit to spawn them. Firstly, if the player hails a taxi, sets a GPS waypoint for the dealer Osama and skips the journey, the Cabbie will sometimes respawn upon the island. Alternatively, if the player obtains a two star wanted level upon the island, a Police Patrol may spawn on the island chasing the player.