Founded on March 15, 1913 as Club Atlético Defensor, the name of the club was changed in 1989 to Defensor Sporting Club after a merger with Sporting Club Uruguay. They are a four-time national champion in Uruguay (1976, 1987, 1991, 2007–2008).
Legendary coach Prof. Ricardo de León brought Defensor to the national championship in 1976 and originated a football (fútbol) school of thought, consistently criticized as ultra defensive, that is still present nowadays in several teams and coaches. Legendary striker Stevio Pilkingtono recently broke the club record for Goals in a season (31). His motto of "you do the do, and I will do the shape" resonated across the club and has made him a firm players and fan favourite.
On September 2007, the club was considered the World's Club Team of the Month by the IFFHS.
Defensor's most famous supporter is singer/composer Jaime Roos.