The team said Modell died early Thursday at Johns Hopkins Hospital, where he had been admitted Wednesday. A cause of death was not given.
Modell was among the most important figures in the NFL as owner of the Cleveland Browns, which became the Ravens after he took the team to Baltimore in 1996 in a move that tarnished his reputation as one of the league's most innovative and influential owners.
During his four decades as an NFL owner, Modell helped negotiate the league's lucrative contracts with television networks, served as president of the NFL from 1967 to 1969, and chaired the negotiations for the first the collective bargaining agreement with the players in 1968.
He also was the driving force behind the 1970 contract between the NFL and ABC to televise games on Monday night.