Club Social y Deportivo Colo-Colo (Spanish pronunciation: [ˌkolo ˈkolo]) is a Chilean professional football club based in Macul, Santiago. Founded in 1925 by David Arellano they play in the Chilean Primera División, from which they have never been relegated. The team has played its home games at Estadio Monumental David Arellano since 1989. Colo-Colo is regarded as the most successful club of Chilean football.

Colo-Colo has won 33 Primera División de Chile titles, more than any other Chilean club and a record thirteen Copa Chile titles. It was the first Chilean team to win a continental tournament, winning the 1991 Copa Libertadores The following year, the club went on to win a further two international titles, the 1992 Recopa Sudamericana and the 1992 Copa Interamericana,

The club's all time top scorer is Esteban Paredes with 216 goals, and the player with most appearances is the former goalkeeper Misael Escuti with 417 games. Luis Mena, dubbed the "historic one", won eleven titles for the club, a Chilean league record.

Colo-Colo is most supported team in Chile, and holds a long-standing rivalry with Universidad de Chile. The club also holds a traditional rivalry in matches against Cobreloa and Universidad Católica. The IFFHS ranked the team in 14th place in 2007. In 2009, the IFFHS also named the team as the top club in Chile for the 20th century, and one of the top twenty clubs in South American football history.