A lens apparatus includes: a fixed barrel with a movable barrel therein holding an optical element and moving along an optical axis; a first operating unit rotatable outside the fixed barrel; a movable stop in the fixed barrel, the stop including a movable unit rotatable to change aperture diameter; a second operating unit outside the fixed barrel; and transmission barrel engaging with the fixed barrel in the fixed barrel and connected to the second operating unit at a first portion and to the movable unit of the stop at a second portion, the transmission barrel having an opening between the first and second portions separated from each other in the optical axis direction, in which the movable barrel is connected to the first operating unit through the opening of the transmission barrel, and moves along the optical axis by a rotation-translation converting mechanism by rotating the first operating unit.