The Pinwheel Galaxy (also known as Messier 101, or NGC 5457) is a face-on, counterclockwise Intermediate spiral galaxy located 21 million light years from Earth in the constellation Ursa Major.

It was discovered by Pierre Méchain in 1781 and was communicated that year to Charles Messier, who verified its position for inclusion in the Messier Catalogue as M101, one of its final entries.

Though the galaxy can be detected with binoculars or a small telescope, to observe the spiral structure in a telescope without a camera requires a fairly large instrument, very dark skies, and a low-power eyepiece.