Duane Charles "Bill" Parcells (born August 22, 1941), also known as "The Big Tuna", is an American football coach. He was a head coach in the National Football League (NFL) for 19 seasons.
He is best known as the head coach of the New York Giants, which he led to two Super Bowl titles. Parcells later was the head coach of the New England Patriots, New York Jets, and Dallas Cowboys.
For a short time, he played for the Detroit Lions in 1964.
Parcells was born in Englewood, New Jersey. He studied at Wichita State University.