C.A. San Isidro

The Club Atlético de San Isidro (mostly known for its acronym CASI) is an Argentine sports club based in the city of San Isidro in Greater Buenos Aires. Originally established as a football club, San Isidro has gained recognition for its rugby union team, holding a record of 33 Torneo de la URBA championships. The senior squad currently competes at Top 12, the top division of the Unión de Rugby de Buenos Aires league system.

San Isidro has also a notable past in football, with 28 consecutive seasons playing in Primera División, the top division of Argentine football league system until the club disaffiliated from the Association when the sport became professional in Argentina. Until then, San Isidro had achieved some international titles such as three Copa de Competencia Jockey Club, one Copa de Honor Municipalidad de Buenos Aires and one international Tie Cup. Nowadays, football is practised at the institution with youth and senior amateur competitions for men and women.

The field hockey section has women's and men's team competing at Metropolitano championships organised by the Buenos Aires Hockey Association.

Apart from rugby, hockey and football, other disciplines hosted by San Isidro are artistic gymnastics, basque pelota, bowls, gaelic football, golf, squash, swimming, taekwondo and tennis.