A traffic light detection device uses an image pickup unit mounted on a vehicle to extract, from an image taken of surroundings of the vehicle, synchronized pixels, whose brightness changes in synchronization with an alternating current period of electric power supplied to a traffic light, and detects the traffic light from the synchronized pixels. The traffic light detection device is provided with: a positional variation calculation unit that calculates positional variation amounts of continuously extracted positions of the synchronized pixels; and a signal lamp determination unit that determines, as a signal lamp candidate, the synchronized pixels whose positional variation amount is equal to or smaller than a threshold value.