Born in Blaengarw, and educated at Garw Grammar School, Young played five times for the Welsh Secondardy Schools between 1959-61 before graduating into senior rugby via his home village club. He played for St Luke's College, Exeter, where he qualified as a teacher, and helped Bridgend win the Unofficial Welsh Championship in 1964/65. After leaving St Luke's, he took up a teaching appointment in Harrogate, where he worked for the next seven years.
His advances on the playing front saw him feature in the East Wales side that drew 3-3 with the 1967 touring All Blacks and then earn the first of his caps in the 5-0 home win over Scotland in 1968. He was never dropped by Wales until Bobby Windsor finally took over from him as the Wales No 2 in 1974, although he did miss games through injury. The third Welsh hooker in five matches, following on from Brian Rees and Norman Gale, he then dominated the position for the next five years.
His debut season on the international front ended with him being called into the British & Irish Lions squad for the 1968 tour to South Africa and he played nine times on that tour. He beat John Pullin to the Test spot for the first international, but was then dropped. He was at the heart of the Welsh pack that won the championship and the Triple Crown in 1969, but suffered a broken jaw on the tour to New Zealand shortly after when Colin Meads punched him for holding onto his jersey at a line-out in the first test in Christchurch.
Young returned to play a key role in the 1971 Grand Slam side and was part of the team that went eight games without defeat between 1970-72.
"Jeff was one of those players you always wanted on your side. He had high nuisance value and was always great fun to have around," said Mervyn Davies, who played with Young for London Welsh and Wales.
In 1971, Young left teaching and joined the RAF, rising to the rank of Wing Commander and earning an OBE for his work in the service. He eventually left in 1991, after he was head hunted by the WRU to become their first Technical Director. He coached the RAF and the British Combined Services, on their joint tour with British Police in New Zealand in 1988, and also acted as team manager at his home town club of Bridgend for a short while.
In his new job at the WRU he quickly earned a reputation for being a modern thinker on the game as it moved rapidly towards professionalism and the man who put some structure and organisation into the Union's coaching and development departments. During that time he urged the coaches in Wales "to find ways to unlock the playing talent, sell a philosophy of fitness and awareness and start playing rugby the way we used to".
He urged Welsh players to adopt a more positive attitude in their bid to improve on the world stage after the failure by the Wales side to qualify for the quarter-finals at the 1995 Rugby World Cup. Young left the WRU in 1996 and returned to Yorkshire, spending two years as Director of Rugby at Harrogate rugby club before returned to teaching at the Army Foundation College in the town.