The Mornington Peninsula is a peninsula located south-east of Melbourne, Australia. It is surrounded by Port Phillip to the west, Western Port to the east and Bass Strait to the south, and is connected to the mainland in the north. Geographically, the peninsula begins its protrusion from the mainland in the area between Pearcedale and Frankston. The area was originally home to the Mayone-bulluk and Boonwurrung-Balluk clans and formed part of the Boonwurrung nation's territory prior to European settlement.
Much of the peninsula has been cleared for agriculture and settlements. However, small areas of the native ecology remain in the peninsula's south and west, some of which is protected by the Mornington Peninsula National Park. In 2002, around 180,000 people lived on the peninsula and in nearby areas, most in the small towns on its western shorelines which are sometimes regarded as outlying suburbs of greater Melbourne; there is a seasonal population of around 270,000.
The peninsula is primarily a local tourist region, with popular natural attractions such as the variety of beaches both sheltered and open-sea and many scenic sights and views. Other popular attractions include the various wineries, mazes and the diverse array of water sports made available by the diversity of beaches and calm waters of Port Phillip and Western Port. Most visitors to the peninsula are residents of Melbourne who camp, rent villas and share houses or stay in private beach houses. It is known simply as "The Peninsula" to locals and Melburnians alike, giving rise to the expression "going down the peninsula".