The 2005 Cronulla riots were a race riot in Sydney, New South Wales, Australia. It began in the beachside suburb of Cronulla on 11 December, and spread over to additional suburbs the next few nights.

The riots were triggered by an event the previous Sunday, when an altercation turned physical between a group of youths of Middle-Eastern appearance (referred to as "Lebanese" or "Lebos" by their opponents) and White Anglo-Australian lifeguards on the beach. Following the reporting of this event by the tabloid media and "shock jocks" on local radio, a racially motivated gathering was organised via chain texting for the following weekend.

A crowd gathered at Cronulla on the morning of Sunday, 11 December, and, by midday, approximately 5,000 people had gathered near the beach. The police eventually intervened. Violence spread to other southern suburbs of Sydney, where assaults occurred, including two stabbings and attacks on ambulances and police officers. Travel warnings for Australia were issued by some countries but were later removed.

The riots were widely condemned by local, state and federal members of parliament, police, local community leaders, and residents of Cronulla and adjacent areas. A large number of arrests were made over the subsequent months, from both the initial riot on 11 December and the retaliations over the subsequent nights. Some media were criticised and well-known radio personality Alan Jones was formally censured and fined for his inflammatory broadcasts during that week.

The far-right Australia First Party, in particular its youth wing the Patriotic Youth League, were involved in the riots.