The invention relates to a belt loop sewing apparatus including: a holding unit which holds one of ends in a longitudinal direction of a belt loop disposed in the longitudinal direction; a clamp unit which includes a loop clamp capable of clamping or releasing the other end of the belt loop from a holding position set by the holding unit and which moves the loop clamp in a direction crossing the longitudinal direction; a fork unit which includes, on a tip, a fork formed into a forked shape and interposing the belt loop between the holding unit and the loop clamp, which is rotatable around an axis in the direction crossing the longitudinal direction and movable in the direction crossing the longitudinal direction together with the loop clamp, and which folds one of the ends of the belt loop back toward a central side of the belt loop by a rotation of the fork unit; and a controller which controls the rotation of the fork unit in order to fold the one of the ends of the belt loop back toward the central side of
