A traffic light detection device capable of properly selecting a traffic light for a detection target depending on an obstruction state of the traffic light is provided. A traffic light detection device (10) includes: an image capture unit (31) that is mounted on a vehicle and captures an image of surroundings; a vehicle location detection unit (11) that detects a location of the vehicle; a map information unit (12) that stores map information; a traffic light location estimation unit (13) that estimates a location of a traffic light around the vehicle with reference to the location of the vehicle and the map information, and sets a traffic light search area in which the traffic light is estimated to be present; a traffic light detection unit (32) that detects the traffic light by searching the traffic light search area on the image; and an obstruction estimation unit (22) that estimates whether a continuous obstruction state where a view of the traffic light is continuously obstructed occurs in the traffic light search area. When the obstruction estimation unit (22) estimates that a continuous obstruction state occurs, the traffic light location estimation unit (13) selects the traffic light search area based on the continuous obstruction state.