A temperature display device of a vehicle is provided, which includes a temperature sensor for detecting a temperature of coolant of an engine, the coolant being switched in circulation state by opening and closing a thermostat, between a first state where the coolant is circulated through a radiator and a second state where the coolant is circulated bypassing the radiator, a display unit for displaying a temperature of the coolant, and a controller for controlling a display mode of the display unit based on the detected temperature by the temperature sensor. When the detected temperature changes within a first temperature range where the thermostat is in an open state, the controller changes the displayed temperature on the display unit by less than the change of the detected temperature.