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.
The R-C prescription remains the predominant optical design for telescopes and has since been used for the majority of major ground-based and space-based telescopes.
He worked closely with George Ellery Hale, first at Yerkes Observatory and later at Mt.
Wilson Observatory.
He played a major role in designing the mountings and making the mirrors of the Mt.
Wilson 60-inch (1.5 m) and 100-inch (2.5 m) telescopes.
Hale and Ritchey had a falling out in 1919, and Ritchey eventually went to Paris where he promoted the construction of very large telescopes.