During a lengthy playing career as a defender, Kinnear played for Spurs and Brighton and Hove Albion, and also won 26 caps for the Republic of Ireland. As a player, he won the FA Cup, the League Cup, twice, and the UEFA Cup while playing for Tottenham. He retired in 1977 after a knee injury.
He enjoyed a varied managerial career, stepping into the dugout to take charge of India, Nepal, Doncaster Rovers, Wimbledon, Luton Town and Nottingham Forest, as well as Newcastle, where he both managed and served as a director of football.
He left the game in 2014, and was diagnosed with dementia the following year.