Dewey is a masculine given name. Notable people with the name include:
Dewey Balfa (1927–1992), American musician
Dewey Bartlett (1919–1979), American politician
Dewey Bunnell (born 1951), American musician
Dewey E. Burchett, Jr. (1939-2009), American judge
Dewey Cooper (born 1974), American kickboxer and boxer
Dewey Lambdin (born 1945), American novelist
Dewey McClain, American football player and politician
Dewey Martin (actor) (born 1923), American actor
Dewey Martin (musician) (1940–2009), Canadian drummer
Dewey Nicks (born 1961), American photographer
Dewey Redman (1931–2006), American jazz saxophonist
Dewey Robinson (1898–1950), American actor
Dewey Short (1898–1979), American politician
Dewey Smith (1972–2009), American aquanaut
Dewey Weber (1938–1993), American surfer
Fictional characters:
Dewey Cox, fictional character in the 2007 film Walk Hard: The Dewey Cox Story
Dewey Denouement, fictional character in the A Series of Unfortunate Events novels by Lemony Snicket
Dewey Finn, fictional character in the 2003 film School of Rock
Dewey Novak, fictional character in the television series Eureka Seven
Dewey Riley, fictional character in the Scream films
Dewey (Malcolm in the Middle), fictional character in the television series Malcolm in the Middle
Huey, Dewey and Louie, fictional nephews of Donald Duck