A seat damper attached between a vehicle body and a seat in a seat suspension structure. The seat damper capable of allowing misalignment of mounting positions of mounting parts between the vehicle body side and the seat side, and being configured with reduced rigidity. The seat damper includes: a resilient member interposed between a vehicle body and a seat, supporting a load applied thereto; a seat-side bearing plate and a vehicle body-side bearing plate sandwiching the resilient member; a rod including a joint for pivotably coupling the rod to the seat-side bearing plate and a locking portion at the other end locking the rod to a lower face of the vehicle body-side bearing plate, with this joint being received in and locked to the seat-side bearing plate; and a ring-like rod guide provided to the vehicle body-side bearing plate for the rod to pass through.