Joseph Leonard Sinnott (; October 16, 1926 June 25, 2020) was an American comic book artist. Working primarily as an inker, Sinnott is best known for his long stint on Marvel Comics' "Fantastic Four", from 1965 to 1981 (and briefly in the late 1980s), initially over the pencils of Jack Kirby. During his 60 years as a Marvel freelance artist and then salaried artist working from home, Sinnott inked virtually every major title, with notable runs on "The Avengers", "The Defenders", and "Thor".