John McCarthy (born September 4, 1927, in Boston, Massachusetts, sometimes known affectionately as Uncle John McCarthy), is a prominent computer scientist who received the Turing Award in 1971 for his major contributions to the field of Artificial Intelligence. He was responsible for the coining of the term "Artificial Intelligence" in his 1955 proposal for the 1956 Dartmouth Conference.

John Patrick McCarthy CBE (born November 26 1956) is a British journalist who was kidnapped by terrorists in Lebanon in April 1986, and held hostage for more than five years.

John McCarthy (born 1953 in Medford, Massachusetts) is a linguist and professor in the Department of Linguistics at the University of Massachusetts Amherst with a speciality in phonology and morphology. He was educated at Harvard University and MIT and was responsible, along with Alan Prince, for extending autosegmental phonology, and later Optimality Theory, to morphology.