A beam steering radial line slot array (RLSA) antenna with reconfigurable operating frequency is proposed in this paper. The RLSA antenna is fed by an aperture coupled structure, which incorporates PIN diode switches that are integrated with the feed line. It is found that the beam steering ability and reconfigurable operating frequency are greatly influenced by the spiral and radius of feed line respectively. The activation of certain PIN diode switches configuration would then determine the beam steered angle and the frequency of operation. This novel antenna design is capable of steering its radiated beam to four different angles; 0°/360°, 90°, 180°, and 270°. Furthermore, the proposed antenna can be configured to operate from a single centre frequency, up to four operating centre frequencies concurrently, at each steered beam direction. The four frequencies are 2.3 GHz, 2.6 GHz, 2.9 GHz and 3.3 GHz. This antenna is a promising candidate to be installed for a smart antenna system, cognitive radio, radar or direction finding applications in the future.