The 1919 Fremantle Wharf riot, also known as the Battle of the Barricades, arose out of a strike by stevedores in Fremantle, Western Australia in 1919. The strike was called by the Waterside Workers' Federation (WWF) over the use of National Waterside Workers Union (NWWU) workers to unload the quarantined ship Dimboola, and escalated into fatal violence when WWF workers and supporters attempted to prevent NWWU members from carrying out the work.

Fremantle 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.