The objective lens for an endoscope substantially consists of a first lens group having a negative refractive power, a stop, and a second lens group having a positive refractive power in this order from the object side. The first lens group consists of a single negative lens. The second lens group consists of two or fewer lenses. When the focal length of the first lens group is f1 and the focal length of the entire system is f, conditional expression (1): −0.9
