An apparatus and method for calibrating transmission paths in a multicarrier communication system using multiple antennas are provided. In the transmission path calibrating apparatus, a calibration processor generates reference signals to estimate distortions in phase and amplitude in transmission paths, allocates the generated reference signals to subcarriers which are different in each of the transmission paths, and calculates calibration vectors for the transmission paths using the generated reference signals and received reference signals received through the transmission paths. A baseband module IFFT-processes the generated reference signals allocated to the subcarriers and sends the IFFT signals in the transmission paths.