Provided is a rotary damper that makes it possible to adjust braking torque characteristics. A rotary damper (1) that restricts the movement of a viscous fluid (6) with which the inside of a cylindrical chamber (200) of a case (2) has been filled and thereby generates braking torque against applied rotational force. A flow path (208) is formed in a partitioning part (204) of the cylindrical chamber (200), and a check valve (3) is movably arranged inside the flow path (208). When a rotor (4) has rotated in a normal rotation direction R1, the check valve (3) moves inside the flow path (208) in a closing direction M1 and closes the flow path (208) and, when the rotor (4) has rotated in a reverse rotation direction R2, moves inside the flow path (208) in an opening direction M2 and opens the flow path (208). The check valve (3) comprises a reaction force application part (302) that generates a reaction force against the check valve (3) when the check valve (3) has moved to a prescribed position in the closing direction M1.