Società Sportiva Lazio was founded on 9 January 1900 by a group of Italian army officers in Rome's Piazza della Libertà, making it the oldest of the capital's clubs and one of the oldest in all of Italy. The club takes its name from the Lazio region surrounding Rome and adopted the sky-blue (biancoceleste) colours of Greece, in honour of the ancient Olympic ideals — Lazio is also a multi-sport polisportiva covering many disciplines.
Lazio's first Serie A title arrived in 1973-74, an era defined by the goalscoring of Giorgio Chinaglia and the tactical work of Tommaso Maestrelli. The club's most decorated period followed under owner Sergio Cragnotti from the late 1990s. The 1999-2000 squad — featuring Pavel Nedvěd, Hernán Crespo, Marcelo Salas, Juan Sebastián Verón, Alessandro Nesta and Diego Simeone — won the second Scudetto, the Coppa Italia, the Supercoppa Italiana, the UEFA Cup Winners' Cup (1998-99, the final edition of the competition), and the UEFA Super Cup. That clean sweep ranks among the greatest single-season hauls in Italian football history.
The post-Cragnotti era brought financial restructuring under Claudio Lotito, who has owned the club since 2004. Three more Coppa Italia titles followed in 2009, 2013 and 2019, the latter two against rivals Roma. The Derby della Capitale against Roma — one of football's fiercest urban derbies — remains the defining fixture of the Lazio identity, contested in the shared Stadio Olimpico. The club's eagle (aquila) emblem and the "Le Aquile" nickname trace back to its Roman imperial associations.