In a guide groove of a guide rotator of a valve timing control apparatus, a stopper surface is planar and is positioned in an end of the guide groove. The stopper surface is engageable with a cylindrical outer peripheral surface of a movable body, which is received in the guide groove, to stop the movable body. An arcuate outer connection surface connects between the stopper surface and an outer guide surface and has a radius of curvature, which is smaller than that of the cylindrical outer peripheral surface of the movable body. An arcuate inner connection surface connects between the stopper surface and an inner guide surface and has a radius of curvature, which is smaller than that of the cylindrical outer peripheral surface of the movable body.