A portable fishing spool tool for quickly, easily and safely re-spooling new fishing line onto any size fishing reel, and unwinding old fishing line from any size fishing reel, in a controlled manner to prevent injury or damage to users or fishing equipment during the process. The fishing spool tool includes a spool mounted on a rod, a tension spring system including a rod collar, and tension collar assembly both mounted on the rod at opposite sides of the spool to permit users to adjust axial tension on the spool to control rotational speed and drag of the spool when adding or removing fishing line. One end of the rod is attachable to a power drill to unwind fishing line, and a pair of suction cups are attachable to opposite ends of the rod to install the spool tool in a receptacle with a ballast for re-spooling fishing line on fishing reels.