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.
The peninsula was formed by the flooding of Port Phillip Bay after the end of the Ice Age about 10000 BC. It may have extended into Port Phillip at various times, most recently between 800 BC and 1000 AD when Port Phillip Bay may have dried out.
Indigenous Australians of the Mayone-bulluk and Boonwurrung-Balluk clans lived on the peninsula as part of the Boonwurrung People's territory prior to European settlement. The territory hosted six clans who lived along the Victorian coast from the Werribee River across to Western Port Bay and Wilsons Promontory. The peninsula may have been home to between 100 – 500 people prior to European settlement.