A K-band dual circularly polarized (CP) and multiple mode reconfigurable orbital angular momentum (OAM) hexagonal antenna array (HAA) is presented. The proposed HAA consists of twelve dual CP horn antenna elements. By controlling the port input phase of each horn antenna element, the OAM modes generated by the proposed HAA can be reconfigured between l = 0, ±1, ±2, and ±3 for both left-hand CP (LHCP) and right-hand CP (RHCP). Moreover, the LHCP and RHCP modes can operate simultaneously under the same radiation aperture. The simulated results verified the effectiveness of the HAA.