Williams, who was christened John James but known throughout the world of rugby by his initials, was regarded as one of the greatest finishers in the sport's history.
During his time with Wales he scored 12 tries in 30 appearances, winning four Five Nations titles, including two Grand Slams in 1976 and 1978 and four Triple Crowns.
Williams’ pace saw him represent Wales at the 1970 Commonwealth Games, but it was for the Lions later that decade that he really shone.
The wing toured South Africa in 1974 and New Zealand in 1977 and his try-scoring exploits put him into the tourists’ record books.
OBITUARY: JJ Williams, one of the greatest wings to play for @LlanelliRFC, Wales and @lionsofficial: https://t.co/HF6byAqUwQ
All our thoughts are with JJ's family and friends at this sad time.
Cysga'n dawel, JJ 🏴 pic.twitter.com/1bNTpP5axJ
— Welsh Rugby Union 🏉 (@WelshRugbyUnion) October 29, 2020
He equalled David Duckham's record of six tries in a single Lions game during a 97-0 victory over South West Districts in 1974, while he also scored four tries in the subsequent 3-0 Test series triumph against South Africa.
That made him only the second Lions player to score two tries twice in a Test and he scored another Test try in New Zealand three years later to finish his career with a five-try Test haul that is only second to Ireland’s Tony O'Reilly.
Williams’ passing on Thursday morning was met with great sadness this morning and one of his former clubs, Bridgend Ravens, tweeted: “All at Bridgend Ravens are deeply saddened to hear of the passing of former player JJ Williams. Our thoughts are with JJ's family and friends at this tough time."
We have lost a true legend of the game – RIP JJ Williams
A man who inspired a generation with his incredible running and finishing abilities
The Welsh winger was a key member of our famous 1974 & 1977 Tours, delivering commanding performances across 7 Tests#LionsRugby pic.twitter.com/g6CXgyS6aJ
— British & Irish Lions (@lionsofficial) October 29, 2020
Another former club Llanelli tweeted: “It is with great sadness that we hear of the passing of the great JJ Williams. We would like to extend our sincerest condolences to his family, friends and former teammates.”
The Welsh Rugby Union added: “The WRU would like to offer sincere condolences to the family and friends of JJ Williams – his wife, Jane, children Kathryn, James and Rhys.”
Coverage in association with QBE Insurance. QBE Insurance helps businesses build resilience through risk management and insurance. For more information go to QBEEUROPE.COM