A vibration suppression device for a rotary machine according to at least one embodiment of the present disclosure is a vibration suppression device for a rotor of a rotary machine including a damper pin movably provided inside a gap of the rotor, the damper pin including a magnet, and a magnetic force generation portion provided in the rotor at a periphery of the gap. The magnetic force generation portion is configured to exert, against the magnet, a magnetic force in a direction pushing the damper pin away from a stick region of the damper pin located on a radially outward side of the rotor in the gap.