A pivot bearing includes a stepped shaft having an enlarged diameter shaft portion and a reduced diameter shaft portion; a plurality of balls of a lower row are interposed between the enlarged diameter shaft portion and a sleeve outer ring surrounding the enlarged diameter shaft portion; a ball bearing including inner and outer rings and a plurality of balls interposed therebetween is provided around the reduced diameter shaft portion so that the inner ring is secured around the reduced diameter shaft portion while applying an appropriate pre-load on the upper end surface of the inner ring, and the outer ring is urged to contact the lower surface thereof intimately onto the upper surface of the sleeve outer ring. The pivot bearing has a reduced number of parts, is facilitated in incorporation into a swing arm, and is expected to be manufactured at a reduced cost.