An optical image stabilizer includes a lens-holding member, first and second actuators driving the lens-holding member in first and second directions, a first guide member fixed to a base member, a second guide member placed between the first guide member and the lens-holding member, and a first ball placed between the base member and the lens-holding member and rolling in association with movement of the lens-holding member. Relative movement of the first and second guide members in a third direction accompanied by rolling of a second ball is allowed and relative movement thereof in a direction different from the third direction is limited by the second ball. Relative movement of the second guide member and the lens-holding member in a fourth direction accompanied by rolling of the third ball is allowed and relative movement thereof in a direction different from the fourth direction is limited by the third ball.