George Willis Ritchey (December 31 1864 – November 4 1945) was an American optician and telescope maker and astronomer born at Tuppers Plains, Ohio.
Ritchey was educated as a furniture maker. He coinvented the Ritchey-Chrétien reflector telescope along with Henri Chrétien.
He played a major role in designing the mountings and making the mirrors of the 60-inch and 100-inch telescopes at Mount Wilson Observatory. He worked closely with George Ellery Hale.
Craters on Mars and the Moon were named in his honor.