The present disclosure relates to a dual-polarized phased array antenna and a dual-polarized phased array weather radar. According to the dual-polarized phased array antenna, a plurality of dual-polarized row feeds are arranged on a horizontal cylindrical support surface to form a dual-polarized antenna in a horizontal cylindrical shape. This allows two polarized signals in a horizontal direction and a vertical direction to be simultaneously received and transmitted, and ensures digital multi-beam signals with constant beam bandwidth, antenna gain, and dual polarization performance. The dual-polarized phased array weather radar provided in the present disclosure uses the formed dual-polarized microstrip patch antenna or a dual-polarized waveguide slot antenna in the horizontal cylindrical shape. This can ensure consistency of weather detected at different scan angles, and improve the accuracy of weather target 3D construction. In addition, this can simplify the calibration requirement of an existing phased array weather radar.