An optical apparatus is disclosed which has a light amount adjusting unit, a lens to be driven by a linear actuator, and a detector for detecting the position of the lens, and which can be reduced in size. The optical apparatus includes a light amount adjusting unit which adjusts a light amount by light shield members translating in a first direction, a vibration type linear actuator which drives the lens in an optical axis direction, a guide member which guides the lens in the optical axis direction, and a detector which detects the position of the lens. When viewed from the optical axis direction of the optical apparatus, the vibration type linear actuator, the guide member, and the detector are arranged along an outer surface of the light amount adjusting unit, the outer surface being provided in a second direction orthogonal to the first direction.