An object detection device includes: an object detection portion which detects an object around a vehicle; a support member by which the object detection portion is attached to the vehicle; and a cover member which is provided in at least one of the object detection portion and the support member and extends from the object detection portion side toward the outside of the vehicle, wherein the cover member includes a cover main body portion, a receiving portion which receives a load applied from the outside of the vehicle, and a first fragile portion which is provided between the cover main body portion and the receiving portion, wherein the support member includes a second fragile portion.