Club Atlético de Madrid was founded on 26 April 1903 by three Basque students in Madrid as Athletic Club de Madrid, originally as a youth offshoot of Athletic Bilbao. The two clubs maintained close ties for decades. After a forced merger in 1939 with the Spanish air force club Aviación Nacional during the Spanish Civil War aftermath, the club became Atlético Aviación, and finally Atlético Madrid in 1947. The red-and-white striped shirts — earning the nickname "Los Colchoneros" (the Mattress Makers, as the stripes resembled mattress fabric of the era) — date to its earliest years.
Atlético's 11 La Liga titles place them third all-time in Spanish football, behind only Real Madrid and Barcelona. The club's first golden era spanned the 1940s and 1960s, while the 1973-74 European Cup final — lost in a controversial replay to Bayern Munich after Luis Aragonés equalised in extra time — represented an early high point. The 1962 UEFA Cup Winners' Cup win was the club's first European title. Atlético also won three UEFA Europa League titles (2009-10, 2011-12, 2017-18) and three UEFA Super Cups, plus the 1974 Intercontinental Cup. The club moved from the historic Vicente Calderón to the Riyadh Air Metropolitano (formerly Wanda Metropolitano) in 2017.
Diego Simeone's tenure as manager (December 2011-present) is the longest in modern Spanish football history. Under "El Cholo," Atlético broke Real Madrid and Barcelona's 16-year duopoly with La Liga titles in 2013-14 and 2020-21, twice reaching UEFA Champions League finals (2014 and 2016, both lost to Real Madrid). Simeone's intensely defensive, combative style — combined with stars like Diego Forlán, Sergio Agüero, Diego Costa, Antoine Griezmann, Koke and Jan Oblak — defines the modern club. The fierce El Derbi Madrileño against Real Madrid is the club's defining fixture. Co-presidents Miguel Ángel Gil Marín and Enrique Cerezo have led the ownership since the late 1980s.