Provided is a radar signal processing method and apparatus for compensating for an in-phase/quadrature-phase (I/Q) imbalance, the method including extracting a real part of a radar signal in which an I/Q imbalance occurs through a conversion of an in-phase (I) channel signal of the radar signal, extracting an imaginary part of the radar signal through a conversion of a quadrature-phase (Q) channel signal of the radar signal, extracting an error due to the I/Q imbalance based on the real part and the imaginary part, and outputting a correction signal obtained by compensating for the I/Q imbalance of the radar signal based on the error.