An optical deflection element is configured to include a prism electrode provided on an optical waveguide, a first photonic crystal structure provided forward of the prism electrode in a light traveling direction being a position after a light passes through the prism electrode, a control electrode provided to confront a counter electrode layer via the optical waveguide on the first photonic crystal structure, and a second photonic crystal structure provided in the lateral direction of the prism electrode in parallel with the light traveling direction.