The oscillating spatial modes of a phase‐locked injection laser array are observed by spectrally resolving its far‐field radiation pattern. The origin of the observed far fields is not consistent with a uniform array of emitters with equal coupling between the elements. When the array is placed in an external cavity containing a mirror, it is possible to select individual spatial modes of the compound resonator, including the fundamental mode. Operation of a phase‐locked laser array in conjunction with an external resonator is shown to be a useful technique for spatial mode selection.