An optical element driving mechanism includes an optical element, a fixed assembly, a movable assembly, and a driving assembly. The optical element has an optical axis. The movable assembly is movably with respect to the fixed assembly and configured to hold the optical element. The driving assembly is configured to drive the movable assembly to move relative to the fixed assembly. When viewed along the optical axis, the optical element driving mechanism with a rectangular structure has a long side and a short side, and a length of the long side is not equal to a length of the short side.