In this correspondence, we propose a blind carrier phase synchronization algorithm for high-order M-ary quadrature amplitude modulation-orthogonal frequency division multiplexing (M-QAM-OFDM) systems, which can effectively recover residual frequency offset (RFO) in the presence of intercarrier interference (ICI). The proposed algorithm performs frequency and phase synchronization by using post-fast Fourier transform (FFT) demodulated signals without the aid of reference signals (e.g., pilots, guard intervals, and virtual carriers), and is simple to implement. By analyzing its open-loop characteristics, we show that the proposed algorithm is superior to the conventional decision-directed (DD) scheme for high-order M-QAM-OFDM systems.