An object is to provide an optical element in which a wavelength dependence of refraction of transmitted light is small, and a light guide element including the optical element. The optical element includes: plurality of optically-anisotropic layers that are formed using a composition including a liquid crystal compound and have a liquid crystal alignment pattern in which a direction of an optical axis derived from the liquid crystal compound continuously rotates in one in-plane direction; and a wavelength selective phase difference layer that is disposed between two optically-anisotropic layers and converts circularly polarized light in a specific wavelength range into circularly polarized light having an opposite turning direction, in which, in a case where, in the liquid crystal alignment pattern, a length over which the direction of the optical axis rotates by 180° in the in-plane direction in which the direction of the optical axis changes is set as a single period, a length of the single period in at least one optically-anisotropic layer is different from that of another optically-anisotropic layer.