Dennis Coughlin played for Exeter City in 1968 when on loan from Swansea. After playing in the reserves at Barnsley, and then moving into non-league football, he had finally made his Football League debut for Bournemouth at the age of twenty-five. He finished his career with South Shields in his native County Durham.Aged twenty, and playing for Durham City, he was offered his first chance in professional football when he signed for Barnsley in October 1957. Never playing a league game for his new club, he subsequently joined Yeovil Town from where he moved to Bournemouth & Boscombe Athletic in March 1963. Making a belated Football League bow, Dennis netted 40 goals in 88 league outings for the Cherries before leaving for Swansea Town in August 1966.
Adding another ten goals in 40 league outings during his time in South Wales, Dennis spent a brief period on loan with Exeter City starting with a debut against Barnsley on 9 March 1968. Wearing the number nine shirt for thirteen games, he scored twice against Hartlepools and York.
Leaving Swansea at the end of the season, he joined Chelmsford City and later played for King's Lynn and Bedford Town before returning to the North East with South Shields. Settling in Hetton-le-Hole, he worked at ICI in Billingham ICI and for an offshore engineering company in Wallsend.