Bamba returned to the squad at the beginning of the 2017–18 season, helping Cardiff win their three opening games of the season, for the first time in their history. He signed a new three-year contract on 25 August 2017, following it up by heading in the winner against Queens Park Rangers the next day. He went on to help the club win promotion to the Premier League after finishing the season in second place. He was ever present in the league, appearing in all 46 league matches, and was named in the PFA Championship Team of the Year.