A thermoelectric generator for a vehicle utilizing heat of exhaust gas discharged from an engine of the vehicle includes a heat exchange unit, through which a coolant circulates, a thermoelectric generation unit for converting thermal energy of exhaust gas into electrical energy, a first flow passage for guiding the exhaust gas to pass through the heat exchange unit, a second flow passage for guiding the exhaust gas to pass through the thermoelectric generation unit, a third flow passage for guiding the exhaust gas to bypass the heat exchange unit and the thermoelectric generation unit without passing therethrough, a first valve for opening or closing the first flow passage, a second valve for selectively opening or closing the second flow passage and the third flow passage, and a driving unit for operating the first valve and the second valve by a single power source.