John Warren Aldrich (February 23, 1906 – May 3, 1995) was an American ornithologist.
Aldrich was born on February 23, 1906, in Providence, Rhode Island. He went to Providence public schools, and got a BS degree in biology from Brown University, in 1928. In 1923 in Bird-Lore he published his first work "Mocking Bird in Rhode Island", which became very popular among Rhode Islanders interested in bird-watching. While attending Brown University, he joined a swimming team there, and set a record for the whole school on 200-yard breaststroke. He was a nature counselor at Camp Chewonki, in Maine. After graduating from Brown University, he attended Buffalo Museum of Science, which had just been built. There he served as an aid and assistant. While working there, he met Roger Tory Peterson, then an art student from Jamestown, New York. Aldrich got a biological assistant position in 1930, at the Cleveland Museum of Natural History, where he worked under supervision of Harry Oberholser. He met his love, Louise Kendall, in Cleveland, and went to Niagara Falls in 1933.
Aldrich did lots of field work, in numerous states, including: Michigan, Ohio, Wyoming, and Ontario, Canada, which was under control of CMNH. He got multiple skin cancers while working in the sun. Later on, attended Western Reserve University, in which he earned an MA degree in biology, in 1937. During the same year, he also got a PhD, from the same university. After the PhD, he was appointed as a curator of birds at a museum.