A bicycle rear derailleur comprises a first member, a second member and a locking structure. The second member is pivotally attached to the first member about a pivot axis. The locking structure fixes a relative position of the first and second members with respect to a rotational direction about the pivot axis. The locking structure is configured to release the relative position of the first and second members from a fixed state upon a predetermined load being provided to one of the first and second members in the rotational direction with respect to the pivot axis.