Provided is an optical modulator module in which a modulation substrate having a plurality of optical modulation units is stored inside a package case. The optical modulator module includes a plurality of signal supply lines configured to supply a modulation signal to the optical modulation unit through a connector terminal which is introduced into the package case. At least two or more of the plurality of signal supply lines are set such that the signal supply lines have overall electrical lengths which are different from each other. A particular part of the signal supply line employs at least one of the following configurations (a) and (b): (a) setting the signal supply line having a longer overall electrical length to have a wider cross-sectional area of a surface perpendicular to a direction in which the modulation signal propagates; and (b) setting a cross-sectional area of the particular part to be wider than cross-sectional areas of parts other than the particular part and setting the signal supply line having a longer overall electrical length to have the particular part increased in length.