This paper presents a high gain, wideband circularly polarized (CP) antenna. High gain of the antenna is achieved by employing a frequency selective surface (FSS) as a reflector. The antenna is a coplanar waveguide-fed structure with a modified L-shaped radiating patch. The unit element of the FSS is formed by connecting two modified dipoles at an angle of 90°. The antenna with reflector has a measured impedance bandwidth of 74.3% (2.2–4.8 GHz) and a 3-dB axial ratio bandwidth (ARBW) of 62% (2.2–4.18 GHz). The maximum boresight gain of the proposed antenna with reflector is 7.1 dB at 3.4 GHz. The radiation patterns of the antenna with the FSS are also measured and compared with simulated patterns. The various aspects of effect of FSS on CP antenna performance are also discussed.