During the Second World War the government imposed a fifty mile travelling limit on all football teams and the Football League divided all the clubs into seven regional areas where games could take place. Wolves joined the Midland League with West Bromwich Albion, Birmingham City, Coventry City, Luton Town, Northampton Town, Leicester City and Walsall. Dunn made 100 unofficial wartime appearances.
After the war he joined a team that included Dennis Westcott, Johnny Hancocks, Sammy Smythe, Jesse Pye, Jimmy Mullen, Billy Crook, Roy Pritchard, Billy Wright, Bert Williams, Bill Shorthouse and Terry Springthorpe. However, in the 1946/47 season he only made three appearances for the club.
The following season he was a regular member of the first-team. Despite taking Wolves to third place in the 1946-47 season Ted Vizard was replaced by his assistant Stan Cullis in June 1948. The following year Cullis led Wolves to the FA Cup final against Leicester City. Wolves won the game 3-1 with Jesse Pye scoring two goals in the first-half and Sammy Smythe netting another in the 68th minute.
The following season Wolves finished in 2nd place in the First Division. However, Dunn missed most of the season with a back-injury. After scoring 33 goals in 123 league games, Dunn was transferred to Derby County in November 1952 for a fee of £15,000.
Dunn joined Worcester City after Derby was relegated to the Third Division in 1955. He had scored 21 goals in 57 games for the club. After retiring from football he ran a pub in Penn before qualifying as a physiotherapist. In this role, he became a trainer at West Bromwich Albion in 1963. Later he ran his own clinic in Edgbaston.