Former teammates Harry Carson and Brian Kelley told the New York Daily News that the body of the former Michigan State All-American was found Tuesday by his fiancee in a chair at the home the couple recently purchased together.
With Carson and Lawrence Taylor, the trio was among the NFL's most feared linebacking corps in the late 1970s.
"I'm saddened," Carson told the newspaper. "I lost a teammate and my very good friend."
Van Pelt, 57, was a star at Michigan State and in 1972 was the first defensive back to win the Maxwell Award, symbolic of the nation's top collegiate player.
He was a second round pick by the Giants in the 1973 NFL draft and converted into a linebacker.
Van Pelt was inducted into the College Football Hall of Fame in 2001.