He represented Cardiff RFC between 1963 and 1969, playing over 140 games and his only Welsh cap came during this period, against Scotland in 1967.
He was paired with the young Barry John at half back, two running half backs. They were told to play a kicking game and Wales lost 11 - 5. Both were dropped and though Barry John was to return and carve a great name for himself, Billy Hullin never got another chance. They were two of six new caps in that match.
He had also gained honours for Welsh Schools and was able to show his attacking prowess for the Barbarians for whom he played 9 times between 1967 and 1971 including a match against South African Barbarians in 1969.
He went on to represent Surrey and London Counties sides and also played club rugby for Mumbles, Aberavon, and London Welsh.
The sympathies of Cardiff Blues are with his family at this sad time.
His funeral will be held on Friday 12th October at 11.30am at St Isan Church, Llanishen, Cardiff followed by the cremation at Thornhill Crematorium.