Sexton led Chelsea to the FA Cup in 1970 then guided them to the European Cup Winners' Cup the following season.
He also had international success coaching England's U21 side, winning two European U21 Championships during a long spell in charge from 1977-1990.
Sir Trevor Brooking, the FA's director of football development said: "It is a sad day for English football.
"Anyone who was ever coached by Dave would be able to tell you what a good man he was, but not only that, what a great coach in particular he was.
"In the last 30-40 years Dave's name was up there with any of the top coaches we have produced in England - the likes of Terry Venables, Don Howe and Ron Greenwood. His coaching was revered."
Sexton played for Luton, West Ham, Leyton Orient, Brighton and Crystal Palace before beginning his coaching career at Chelsea.
He first managed Leyton Orient in 1965 and also took charge of Chelsea, QPR and Manchester United before taking the England U21 job. He also managed Coventry in the early 1980s.
Sexton was awarded an OBE in 2005 for services to football.