Provided is a magnetic fluid sealed bearing with which torque can be reduced without impairing a water and dust proof effect. A magnetic fluid sealed bearing according to the present disclosure includes a magnetic fluid retained by a ring-shaped magnet in an opening between an inner ring and an outer ring to seal a plurality of rolling members. The magnet is magnetized such that their magnetic poles point to an axial direction. The bearing further includes a ring-shaped outer polar plate and a ring-shaped inner polar plate sandwiching the ring-shaped magnet therebetween, one side of the polar plates being fixed to one of the inner ring and the outer ring, and the other side of the polar plates facing a clearance.