Having earlier made nearly 70 league appearances for Coventry City, Dennis Simpson joined Exeter City in 1955 from Reading where he had played 172 league matches. Arriving at St James’ Park aged 35 he played on a part-time basis whilst working in engineering in Exmouth. He later played for Exmouth Town.

Spotted playing for Salem Baptist in Coventry, Dennis was signed as a professional by Coventry City in May 1939. With the outbreak of war his Football League debut was delayed until 1946/47 and he eventually made 67 appearances (scoring five goals) for the club. He signed for Reading in May 1950 and remained at Elm Park for five seasons during which time he figured in 172 league matches and scored 32 goals.

Dennis moved to Exeter City at the age of 35 in May 1955 and made his debut for the Grecians in a goalless draw at home to Colchester United on 20 August 1955. A part-time player - who made 27 league appearances in 1955/56 but just three more at the very start of the following campaign -  he was working as an engineer in Exmouth and eventually left City when his contract was cancelled because of difficulties in attending training. Initially remaining in the area, Dennis played for Exmouth Town ahead of returning to Coventry where he lived until his death on 10 January 2002.