In a one-way clutch integrated with a rolling bearing, rolling elements and sprags are arranged in an annular space between an inner race and an outer race in each of which a one-way clutch raceway surface is formed in one axial side of a rolling bearing raceway surface. The rolling elements and the sprags make contact with respective raceway surfaces and are respectively housed in circumferentially spaced pockets formed in a common cage configured by mutually engaging and integrating two annular members in an axial direction. The one-way clutch includes urging means for urging the sprags in a locking direction in the pockets. An annular flat plate portion which seals one axial end portion of the annular space between the inner race and the outer race is integrally formed in one of the two annular members constituting the cage. Respective at least one radial and axial through holes are formed in the annular member.