In this paper, a miniature dual polarized L-shaped horn antenna array is presented for millimeter-wave electronically scanned array radar. Through measurements of the L-shaped horn antenna and waveguide feed, the 10 dB return loss for both waveguide ports showed better than 16% bandwidth for 34 to 40 GHz operation. In addition, better than 15 dB isolation was achieved throughout this frequency range. The measured gain of the antenna at 35 GHz is 5.3 dB with 19 dB cross-polarization discrimination. The L-shaped horn antenna demonstrates approximately 96 degree beamwidth in the E-plane and 70 degree beamwidth in the H-plane, which therefore allows for the wide-angle beam scanning for phased arrays. Finally, the L-shaped horn antenna array was implemented as part of a broadband millimeter-wave phased array.