Woorndoo is a town in the Western District of Victoria, Australia. The town is in the Shire of Moyne local government area, 259 kilometres (161 mi) west of the state capital, Melbourne. At the 2011 census, Woorndoo and the surrounding area had a population of 309. The population of the town proper is around 50.
Woorndoo Post Office opened on 15 June 1866 and closed in 1996. A Post Office at Woorndoo Upper opened around 1902 and closed in 1946.
The town in conjunction with neighbouring township Mortlake has an Australian Rules football team Woorndoo-Mortlake competing in the Mininera & District Football League.