Fremantle () (Nyungar: Walyalup) is a port city in Western Australia, located at the mouth of the Swan River in the metropolitan area of Perth, the state capital. Fremantle Harbour serves as the port of Perth. The Western Australian vernacular diminutive for Fremantle is Freo.Prior to British settlement, the indigenous Noongar people inhabited the area for millennia, and knew it by the name of Walyalup ("place of the woylie"). Visited by Dutch explorers in the 1600s, Fremantle was the first area settled by the Swan River colonists in 1829,: 11 and is named after Captain Charles Fremantle, an English naval officer who claimed the west coast of New Holland as British territory. The settlement struggled in its first decades, and in 1850, with the advent of penal transportation to the colony, Fremantle became Australia's primary destination for convicts. The convict-built Fremantle Prison operated long after transportation ended in 1868, and is now a World Heritage Site.
Fremantle was charted as a municipality in 1883, and the following decade its harbour was deepened for commercial shipping, transforming the port into a bustling trade centre and gateway at the height of the Western Australian gold rushes. Declared a city in 1929, Fremantle played a key role in World War II as the largest submarine base in the Southern Hemisphere. Post-war immigration from Europe, particularly Italy, helped shape Fremantle's character, and it rapidly gentrified after hosting the 1987 America's Cup. Today, Fremantle is recognised for its well-preserved Victorian and Edwardian streetscapes and convict-era architecture, and is known as a bohemian enclave with a thriving arts and culinary scene. It is also the traditional home of the Fremantle Football Club, one of two Australian Football League teams based in Western Australia.