An optical apparatus includes a driving unit, a holder holding the driving unit, a moving member holding an optical member and movable by drive of the driving unit, and a guide fixed to the holder in parallel to an optical axis direction. The driving unit is fixed to the holder by a screw and a nut. The nut includes a first plane part. The nut is disposed so that the first plane part of the nut is substantially orthogonal to a line connecting a center of the guide and centers of the screw and the nut when viewed in the optical axis direction.