West Island is a 10 hectares (25 acres)granite island lying 0.8 kilometres (0.50mi) off the southern coast of the Fleurieu Peninsula, South Australia, 7 kilometres (4.3mi) south-west of the town of Victor Harbor. It rises to a maximum height of about 40 metres (130ft) in the south-west. Its main conservation value lies its seabirdcolonies.
West Island was named for its location 2 kilometres (1.2mi) west of the promontory of Rosetta Head. During the 1880s it was quarried for granite to construct the foundations of Parliament House, Adelaide. From 1913 until the mid-1960s it was zoned as a Reserve for Government Purposes and, for a short period, was used by the Adelaide University Regiment as a target for gunnery practice during field exercises. In 1966 it became a fauna reserve. Until about 1970 fishers took little penguins and rabbits to use as crayfishbait, though the population of rabbits on the island was exterminated by 1971 and it was declared a Conservation Park in 1972. In 1973 and 1975 Pearson Island rock-wallabies were introduced to the island.