Ganguly joined the Kolkata Knight Riders team as captain for the Indian Premier League Twenty20 cricket tournament in 2008. The same year, after a home Test series against Australia, he announced his retirement from international cricket. He continued to play for the Bengal team and was appointed the chairman of the Cricket Association of Bengal's Cricket Development Committee. The left-handed Ganguly was a prolific One Day International (ODI) batsman, with over 11,000 ODI runs to his credit. He is one of the most successful Indian Test captains to date, winning 21 out of 49 test matches.Sourav Gangly is the most successful Indian test captain overseas with 11 wins.[8] The Indian team was ranked eighth in the ICC rankings before he became the captain, and under his tenure the team rank went up to second. An aggressive captain, Ganguly is credited with having nurtured the careers of many young players who played under him, and transforming the Indian team into an aggressive fighting unit.

Along with Harshavardhan Neotia, Sanjiv Goenka, Utsav Parekh, and Spanish La Liga side Atlético de Madrid, Ganguly is also the co-owner of Atlético de Kolkata, a franchise of the Indian Super League, which won the inaugural season in 2014.