Gilles Coustellier (born 13 May 1986 in Martigues, France) is a French mountain bike trials cyclist.

[2] Coustellier was UCI junior world champion in the 20-inch category in 2002 and then in the 26-inch category in 2003.

In the UCI elite 26-inch category he has been world champion five times.

Competing with the French team he was team trials world champion in 2011.

[1] Gilles is the younger brother of Giacomo Coustellier, who is also a trials rider.