|Full name||Isacio Calleja García|
|Date of birth||6 December 1936|
|Place of birth||Valle de Cerrato, Spain|
|1958||→ Guadalajara (loan)|
|* Senior club appearances and goals counted for the domestic league only.
† Appearances (Goals).
Safe for a very brief loan spell with CD Guadalajara in the third division, Calleja spent his entire 14-year professional career with Atlético Madrid. He made his La Liga debut on 4 January 1959 in a 0–1 away loss against Real Oviedo, and finished his first season with only nine games (albeit all complete).
From there onwards, Calleja became an important first-team member for the Colchoneros, helping the team to back-to-back Copa del Rey trophies from 1959–61, both won against Real Madrid at the Santiago Bernabéu Stadium. In the 1961–62 European Cup Winners' Cup, which also ended in conquest, he contributed with nine appearances.
On 19 April 1970, Calleja scored his only goal of the season in a 2–0 win at CE Sabadell FC, which granted Atlético the national championship. He retired from football in July 1972 at the end of 1971–72 after winning his fourth Spanish Cup with the team, at the age of 35; during his spell with his main club, he appeared in 420 official matches (77 in the domestic cup and 45 in European competition).
- Atlético Madrid
- UEFA Cup Winners' Cup: 1961–62
- Spanish League: 1965–66, 1969–70
- Spanish Cup: 1959–60, 1960–61, 1964–65, 1971–72
- El 'Chato', el escudo en el corazón ('Chato', emblem in heart); El Mundo Deportivo, 5 November 2004 (Spanish)
- BDFutbol profile
- National team data (Spanish)
- Isacio Calleja at National-Football-Teams.com
- Isacio Calleja – FIFA competition record