The invention relates to a bicycle derailleur comprising a chain guide configured to interact with a transmission chain of the bicycle and movable between a plurality of intermediate positions comprised between an inner position and an outer position, a fixed body adapted for being fixedly associated with a part of frame of the bicycle, an outer connection element rotatably connected to the fixedbody about a first articulation axis and rotatably connected to the chain guide about a second articulation axis parallel to the first articulation axis, an inner connection element rotatably connected to the fixed body about a third articulation axis and to the chain guide about a fourth articulation axis, an actuation arm hinged to the fixed body about the first articulation axis, a cable-clamping washer constrainable to the actuation arm suitable for locking a control cable on the actuation arm, a first fastening station and a second fastening station defined on said actuation arm and configured to fasten the control cable in different positions on the actuation arm, an anti-rotation appendage projecting from said chain-clamping washer and adapted for being inserted in a holding seat ofthe actuation arm, in at least one from the first and the second fastening station.