Società Sportiva Lazio (Italian pronunciation: [sotʃeˈta sporˈtiːva ˈlattsjo]; BIT: SSL; Lazio Sport Club) is an Italian professional sports club based in Rome, most known for its football activity. The society, founded in 1900, plays in the Serie A and have spent most of their history in the top tier of Italian football. Lazio have been Italian champions twice (1974, 2000), and have won the Coppa Italia seven times, the Supercoppa Italiana five times, and both the UEFA Cup Winners' Cup and UEFA Super Cup on one occasion. They also won the 1968-69 Serie B.

The club had their first major success in 1958, winning the domestic cup. In 1974, they won their first Serie A title. The 1990s were the most successful period in Lazio's history, with the team reaching the UEFA Cup final in 1998, winning the UEFA Cup Winners' Cup and UEFA Super Cup in 1999, and clinching the Serie A title in 2000. Due to a severe economic crisis in 2002 that forced president Sergio Cragnotti out of the club along with several star players being sold, Lazio's success in the league declined. In spite of the lower funds, the club has won four Coppa Italia titles since then; in 2004, 2009, 2013 and 2019. Current president Claudio Lotito took charge of the club in 2004, filling the vacuum that had existed following Cragnotti's departure.

Lazio's traditional kit colours are sky blue shirts and white shorts with white socks; the colours are reminiscent of Rome's ancient Hellenic legacy. Sky blue socks have also been interchangeably used as home colours. Their home is the 70,634 capacity Stadio Olimpico in Rome, which they share with Roma. Lazio have a long-standing rivalry with Roma, with whom they have contested the Derby della Capitale (in English \"Derby of the capital city\" or Rome derby) since 1929.

Despite initially not having any parent–subsidiary relation with the male and female professional team (that was incorporated as S.S. Lazio S.p.A.), the founding of Società Sportiva Lazio allowed for the club that participates in over 40 different sports disciplines in total.