A tapered roller bearing includes an inner ring, an outer ring, a plurality of tapered rollers, and a cage. The cage includes: a large-diameter side annular portion and a small-diameter side annular portion that form wall portions in both axial ends of pockets; and a plurality of cage bars. A pressure difference reducing portion is provided which reduces the difference between a pressure in an inner region including a smallest bore diameter portion of an outer ring raceway surface of the outer ring and a pressure in an outer region including a boundary portion between an outer peripheral surface and an axially outer end surface of the small-diameter side annular portion of the cage.