A resonant phase‐locked array of antiguides is demonstrated for the first time. A 10/11 element AlGaAs/GaAs antiguided array is grown by two‐step metalorganic chemical vapor deposition. Longitudinally, the structure consists of two noncollinear sets of antiguides separated by a half‐Talbot distance, an ensemble that acts as a spatial filter. Out‐of‐phase‐mode operation is suppressed both by this diffractive‐type spatial filter and by large interelement loss. Resonant in‐phase‐mode operation is a result of the interelement spacing corresponding to one leaky‐wave half wavelength in the lateral direction. Near the in‐phase‐mode resonance, array modes adjacent to the in‐phase‐mode are discriminated against because they have large radiation losses in the antiguided structure and significant edge diffraction losses in the spatial filter. Stable, diffraction‐limited in‐phase‐mode beam patterns are achieved to 10 times threshold and 450 mW output power.