This paper presents a zeroth order metamaterial substrate integrated waveguide antenna. The antenna is designed to have a compact size based on employing only one composite right/lefthanded cell. The antenna resonates at 6.1 GHz with overall radiator size of 14.4 mm × 8 mm which represents 50% size reduction compared to conventional microstrip patch antenna that operates at the same frequency. The zeroth order mode of the antenna has been verified using analytical explanation and full wave simulations. Moreover, the full wave simulations and experimental measurements have been employed to confirm the antenna matching properties and radiation characteristics.