Mortlake /ˈmɔːtleɪk/ is a town in the Western District of Victoria, Australia on the Hamilton Highway, 50 kilometres (31 mi) north-east of Warrnambool. It is in the Shire of Moyne local government area and the federal Division of Wannon. At the 2001 census, Mortlake had a population of 941, rising to 996 in 2006, and to 1,073 in 2011.
Mortlake is situated at the foot of Mount Shadwell, formed 25,000 years ago. It is believed that it last erupted about 5,000 years ago. The large ejected rocks are called volcanic bombs. They are often egg shaped because they cooled as they were being thrown through the air. These bombs can contain olivine, a green crystal also known as peridot, the birthstone for August. Self-proclaimed as the Olivine capital of Australia, it is also known for its bluestone buildings, with several fine examples dating back to the 1850s visible from the Hamilton Highway.