Cagliari Calcio, commonly referred to as Cagliari (Italian: [ˈkaʎʎari] ), is a professional Italian football club based in Cagliari, Sardinia, that plays in Serie A, the first tier of Italian football. The club currently plays home matches at the 16,416-seat Unipol Domus.

Founded in 1920, they won their only Scudetto in 1969–70, when they were led by the Italian national team's all-time leading scorer, Gigi Riva. The triumph was also the first by a club from south of Rome. The club's best European performance was in the 1993–94 UEFA Cup, reaching the semi-finals before losing to eventual winners Internazionale.

As with the flag of its city, Cagliari's main colours are blue and red. The club badge incorporates the flag of Sardinia.

Before Serie A

Cagliari became the first ever out-right champions of Serie C during the 1951–52 season; prior to that in the league, the championship was shared amongst more than one team. They spent the 1950s from then on in Serie B, losing a promotion play-off in 1954. After descending to Serie C in the early 1960s, Cagliari's rise would be meteoric, eventually achieving promotion to Serie A in 1964.