A unilateral backlight and a unilateral multiview display employ an array of unilateral diffractive elements configured to provide directional light beams having a unilateral direction. A unilateral diffractive element of the unilateral diffractive element array comprises a slanted diffraction grating configured to provide a directional light beam by diffractive scattering of light guided in a light guide. The unilateral multiview display further includes light valves configured to modulate a plurality of directional light beams as multiview image having the unilateral direction.