Joseph Bonaparte Gulf is a large body of water off the coast of the Northern Territory and Western Australia and part of the Timor Sea.

It was named after Joseph Bonaparte, brother of Napoleon and King of Naples (1806-1808) and then Spain (1808-1813) by French explorer and naturalist Nicolas Baudin in 1803.

The Legune (Joseph Bonaparte Bay) Important Bird Area lies at the south-eastern end of the gulf.

[3] The Bonaparte Basin is a large sedimentary basin underlying the gulf and a large part of the Timor Sea, deriving its name from the Joseph Bonaparte Gulf, which has several producing and potential oilfields.

The traditional custodians of the areas around the gulf are the Menhdheyangal people.