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 1 according to the present disclosure includes a magnetic fluid retained by an ring-shaped magnet 21 in an opening between an inner ring 3a and an outer ring 3b to seal a plurality of rolling members 3c. The magnet 21 is magnetized such that their magnetic poles point to an axial direction. The bearing further includes a ring-shaped outer polar plate 22 and a ring-shaped inner polar plate 23 sandwiching the ring-shaped magnet 21 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. The bearing further includes an outer ring magnetic fluid 25b retained at least one of between the outer ring and the outer polar plate, between the outer ring and the inner polar plate, and between the outer ring and the magnet, and an inner ring magnetic fluid 25a retained at least one of between the inner ring and the outer polar plate, between the inner ring and the inner polar plate, and between the inner ring and the magnet.
