A thrust sliding bearing includes a synthetic resin-made bearing body having a hollow cylindrical portion, an annular collar portion, an annular protruding portion, a tubular projecting portion, an engaging projecting portion, and an annular projecting portion; an annular cover having a disk portion, a tubular portion, and an engaging projecting portion; an annular metal plate having an outer disk portion and an inner disk portion; and a thrust sliding bearing which is interposed between the bearing body and an annular lower surface of the outer disk portion of the annular metal plate and renders the annular metal plate rotatable with respect to the bearing body in a direction about an axis of the bearing body.