This optical element includes first to fourth liquid crystal cells that are stacked in the stated order. The first to fourth liquid crystal cells each include: a first substrate in which a first pair of comb tooth-shaped transparent electrodes are disposed; and a second substrate in which a second pair of comb tooth-shaped transparent electrodes are disposed. The extension direction of the first pair of comb tooth-shaped transparent electrodes intersects with the extension direction of the second pair of comb tooth-shaped transparent electrodes. Between two different liquid crystal cells among the first to fourth liquid crystal cells, one of the first pair of comb tooth-shaped transparent electrodes of one of the liquid crystal cells and one of the second pair of comb tooth-shaped transparent electrodes of the other of the liquid crystal cells are electrically connected to each other.