An objective lens for an endoscope consists of a first lens group that consists of a negative lens, a second lens group that consists of a negative lens, a third lens group that consists of a cemented lens, an aperture stop, a fourth lens group that consists of a single lens having positive refractive power or a cemented lens having positive refractive power as a whole, and a fifth lens group that consists of a cemented lens including two lenses having refractive power having signs different from each other and cemented to each other； and the first lens group, the second lens group, the third lens group, the fourth lens group, and the fifth lens group are arranged in this order from an object side toward an image side. The objective lens for an endoscope satisfies a predetermined conditional expression related to the cemented lenses.
