In this paper, a simple subcarrier selection combining technique is proposed for orthogonal frequency-division multiplexing (OFDM) systems with multiple receive antennas. The subcarrier-based selection algorithm is developed in the frequency domain to achieve an optimal selection combining gain for OFDM systems, instead of the antenna-based selection algorithms in the time domain or frequency domain. The proposed technique selects an optimal subcarrier with a maximum channel gain among all the receive antennas with the same subcarrier position, based on the estimated channel frequency response during the training period. Hardware complexity for the proposed technique is minimal since it requires single front-end with multiple receive antennas and single baseband demodulator. It is shown by computer simulation that a significant gain can be achieved by the proposed technique over the conventional selection combining technique for OFDM systems in practical situations.