An optical modulator includes an optical modulation element (102) including a plurality of signal electrodes (112a and the like), a plurality of lead pins (116a and the like) for inputting high frequency signals, and a relay substrate (118) in which conductor patterns (202a and the like) that electrically connect the lead pins and the signal electrodes are formed, and at least one of the conductor patterns in the optical modulator is constituted so that at least one resonant frequency of the at least one of the conductor patterns is different from at least one resonant frequency of at least one of the other conductor patterns.