Abstract: A flat cable jacket slitter including a housing, a longitudinal channel within the housing sized to allow the cable to be moved longitudinally within the channel, a cutting blade within the housing, and a movable cam. The movable cam may be positioned within the housing and configured to move between a threading position that allows the cable to be easily moved longitudinal within the channel without substantially engaging the cutting blade and a cutting position that causes the cutting blade to cut a longitudinal slit into an edge of the jacket when the cable is moved longitudinally within the channel. The movable cam may form a longitudinal sub-channel within the housing.