The 2005 Cronulla riots were a series of sectarian clashes and mob violence originating in Cronulla, New South Wales, and spreading, over the next few nights, to additional Sydney suburbs.

On 4 December 2005, a group of volunteer surf lifesavers was assaulted by a group of young men of Middle Eastern appearance, with several other violent assaults occurring over the next week. These incidents were widely reported and commented on in Sydney media. An initially peaceful crowd gathered in the morning of Sunday, 11 December 2005, and, by midday, approximately 5,000 people gathered at Cronulla beach to protest against a recent spate of violence against locals.

However, fuelled by alcohol, the crowd turned to violence when a young man of "Middle Eastern appearance" was spotted on the beach. He was surrounded by a crowd outside a local hotel and attacked. Retaliatory riots also took place that night and on subsequent nights, resulting in extensive property damage and several more assaults, including one stabbing and even some attacks against ambulance and police officers.