A constant velocity universal joint, comprising: an outer joint member (10, 110) having an inner peripheral surface (12, 112) comprising track grooves (11, 111) that are formed at a plurality of positions on the inner peripheral surface (12, 112) and extend in an axial direction; an inner joint member (20, 120) having an outer peripheral surface (22, 122) comprising track grooves (21, 121) that are formed at a plurality of positions on the outer peripheral surface (22, 122) and in pairs with the track grooves (11, 111) of the outer joint member (10, 110), the track grooves (21, 121) of the inner joint member (20, 120) extending in the axial direction; torque transmitting members (30, 130) interposed between the track grooves (11, 111) of the outer joint member (10, 110) and the track grooves (21, 121) of the inner joint member (20, 120); a track chamfer (13, 113) provided at each boundary portion between each of the track grooves (11, 111) of the outer joint member (10, 110) and the inner peripheral surface (12, 112) of the outer joint member (10, 110); and a track chamfer (23, 123) provided at each boundary portion between each of the track grooves (21, 121) of the inner joint member (20, 120) and the outer peripheral surface (22, 122) of the inner joint member (20, 120), wherein a surface hardness at least one of the track chamfer (13, 113) of the outer joint member (10, 110) or the track chamfer (23, 123) of the inner joint member (20, 120) is set to be lower than a surface hardness of each of the track grooves (11, 111) of the outer joint member (10, 110) and the track grooves (21, 121) of the inner joint member (20, 120) by using heat treatment performed on the outer joint member (10, 110) and the inner joint member (20, 120). an outer joint member (10, 110) having an inner peripheral surface (12, 112) comprising track grooves (11, 111) that are formed at a plurality of positions on the inner peripheral surface (12, 112) and extend in an axial direction; an inner joint member (20, 120) having an outer peripheral surface (22, 122) comprising track grooves (21, 121) that are formed at a plurality of positions on the outer peripheral surface (22, 122) and in pairs with the track grooves (11, 111) of the outer joint member (10, 110), the track grooves (21, 121) of the inner joint member (20, 120) extending in the axial direction; torque transmitting members (30, 130) interposed between the track grooves (11, 111) of the outer joint member (10, 110) and the track grooves (21, 121) of the inner joint member (20, 120); a track chamfer (13, 113) provided at each boundary portion between each of the track grooves (11, 111) of the outer joint member (10, 110) and the inner peripheral surface (12, 112) of the outer joint member (10, 110); and a track chamfer (23, 123) provided at each boundary portion between each of the track grooves (21, 121) of the inner joint member (20, 120) and the outer peripheral surface (22, 122) of the inner joint member (20, 120), wherein a surface hardness at least one of the track chamfer (13, 113) of the outer joint member (10, 110) or the track chamfer (23, 123) of the inner joint member (20, 120) is set to be lower than a surface hardness of each of the track grooves (11, 111) of the outer joint member (10, 110) and the track grooves (21, 121) of the inner joint member (20, 120) by using heat treatment performed on the outer joint member (10, 110) and the inner joint member (20, 120).