A heating apparatus, a heat treatment apparatus, and a heating method are provided. The heating apparatus includes a workpiece support on which a ring-shaped workpiece is placed, a rotary drive assembly, and a heater configured to heat the workpiece. The workpiece support includes a plurality of rotating rollers arranged in a circumferential direction. The rotary drive assembly is configured to rotate the plurality of rotating rollers to rotate the workpiece placed on the workpiece support along a ring shape of the workpiece. The heater includes a heating coil configured to induction-heat the workpiece on the workpiece support at a heating position, and an actuator configured to move the heating coil at the heating position relative to the workpiece to adjust a distance between the workpiece and the heating coil.