Sydney Football Club, commonly known as Sydney FC, is a professional soccer club based in Sydney, New South Wales, Australia. They compete in the top-tier men's league in Australia, the A-League Men. Established in 2004, they were among the eight founding teams for the inaugural 2005–06 A-League season.

Domestically, Sydney FC have won a record five A-League Men Championships, four A-League Men Premierships and two Australia Cups. Additionally, the club has won the OFC Champions League once in international competition.

Before the 2018–19 season, the club’s home ground was the Allianz Stadium in Moore Park. When the NSW Government announced that the stadium would be redeveloped before the 2019 New South Wales state election, the team temporarily played at the Sydney Cricket Ground, Jubilee Oval and Leichhardt Oval. In October 2022, the club returned to the newly rebuilt Allianz Stadium. In 2023, Sydney FC completed their new training and administration facility, Sky Park, in North Ryde.

During the club's first seven years, it was the only A-League team in Sydney, attracting a broad fanbase across the Sydney Metropolitan Area. Sydney FC are Australia's most supported A-League club, with 693,000 fans as of 2023. Its leading supporter group, \"The Cove,\" derives its name from Sydney Cove, a bay on the southern shore of Sydney Harbour. They compete in the local Sydney Derby against cross-town rivals Western Sydney Wanderers. As the two most decorated clubs in the A-League Men and fierce inter-state rivals, the club also shares a long-standing rivalry with Melbourne Victory, known as The Big Blue.

Alex Brosque is the club's all-time top goal scorer, with 83 goals in all competitions. Rhyan Grant has the most appearances for the club, having played 375 games.