An endoscope objective lens substantially consists of four lens groups consisting of, in order from the object side, a negative first lens group, a positive second lens group, a negative third lens group and a positive fourth lens group. During focusing from the farthest object to the nearest object, the first lens group is fixed, and the second lens group and the third lens group are moved along the optical axis. The third lens group includes a cemented lens that is formed by a positive lens and a negative lens cemented together in this order from the object side, and the cemented surface of the cemented lens is oriented such that the concave surface faces the object side.
