A rear derailleur is basically provided with a base member, a movable member, a chain guide, a friction element, a one-way clutch and an electric actuator. The base member is configured to be mounted to a bicycle. The movable member is movably coupled to the base member. The chain guide is coupled to the movable member to rotate around a rotational axis with respect to the movable member. The friction element is operatively arranged between the movable member and the chain guide to frictionally provide rotational resistance in a first rotational direction of the chain guide. The one-way clutch is operatively disposed between movable member and the chain guide to engage the friction element as the chain guide rotates in the first rotational direction. The electric actuator is operatively coupled to the one-way clutch to control the one-way clutch between a clutch-on mode and a clutch-off mode.