A spool braking device includes a conductor, a magnetic unit, and a support portion. The conductor has a rotational surface, and is configured to rotate in conjunction with a spool rotatably supported by a reel body. The magnetic unit has at least two magnets arranged on a surface facing the rotational surface of the conductor. The support portion movably supports the magnetic unit between a separated position that is separated from the rotational surface of the conductor and a proximal position that is proximate to the rotational surface of the conductor. The biasing member is configured to bias the magnetic unit from the proximal position to the separated position.