Oceania (sometimes Oceanica) is a geographical, often geopolitical, region consisting of numerous lands—mostly islands but usually including Australia—in the Pacific Ocean and vicinity. The exact scope of Oceania is defined variously, with interpretations including Australia, New Zealand, New Guinea, and various islands of the Malay Archipelago.

The primary use of the term Oceania is to describe a macrogeographical region that lies between Asia and the Americas, with the Australian continent as the major landmass and consisting of some 25,000 islands in the Pacific. The name Oceania is used because, unlike the other regional groupings, it is the ocean and adjacent seas rather than a continent that link the lands together.