Abstract: There are provided an optical communication apparatus, an optical communication system, and an optical communication method that are capable of suppressing deterioration in quality of an output signal. An optical relay apparatus includes a coherent receiver front-end unit that coherently detects an input optical signal to be input, based on local oscillation light, a coherent transmitter front-end unit that coherently modulates and outputs the coherently detected signal, a wavelength meter that monitors a characteristic of the input optical signal, and a wavelength conversion control unit that controls a characteristic of the local oscillation light, based on the monitored characteristic.