A bicycle derailleur includes a mounting member, at least one linkage member, a movable chain guide and a chain guide tensioning mechanism. The mounting member is configured to be attached to a bicycle frame. The linkage member is supported to the mounting member. The movable member is movably coupled to the mounting member via the linkage member. The chain guide is pivotally connected to the movable member to pivot about a pivot axis that extends through the movable member. The chain guide also supports a guide pulley and a tension pulley. The chain guide tensioning mechanism is supported to the movable member at a point spaced apart from the pivot axis configured to bias the chain guide in a direction about the pivot axis.