Mendy was undoubtedly one of the best foreign players of the 2014 ISL and his bicycle kick strike in the home win over Kerala Blasters was one of the goals of the tournament.
Primarily a defender, the former PSG player was used in different positions at Chennaiyin FC last year and he also made contributions going forward. The Frenchman made 13 appearances for CFC in the inaugural ISL and his consistency also saw him earn a place in the team of the tournament.
Mendy, who has been capped four times for France at senior international level, was playing for AEL Limassol in the top tier of Cyprus after ISL 2014.
Chennaiyin FC manager Marco Materazzi said, "We are delighted to have retained Mendy for the second edition of the Hero Indian Super League. Mendy is a leader both on and off the pitch and provides us immense strength and quality. His experience and technical quality makes him a very important player in our squad."