Hailing from the Scottish Borders town of Jedburgh, Glen Young started playing rugby in primary school playing primarily at full-back before moving into the pack at the age of 16. The Borderer first played a part in the Falcons Under 18s side in the 2012-13 season, during which he also made several appearances for the club's A Team. The following season saw Young become an A-Team regular whilst maintaining dual registration with Darlington Mowden Park. In 2014-15 he made his first team debut while also representing Scotland Under-20s for the first time in their game against Ireland. He would go on to receive seven caps at Under 20 level, including a trip to New Zealand as part of Scotland’s Junior World Championship squad in 2014. Having signed a contract extension with Newcastle Falcons midway through that season, 2014/15 represented Young’s first as a full time member of the Falcons' senior academy. Young started the 2015/16 term on dual registration with Championship side Doncaster Knights, playing for them in the Championship play-off final and returning to the Castle Park club during 2016-17, a season which saw him named in the Championship Dream Team. Making his Premiership debut during the 2016-17 season, Young made one top-flight appearance the following year and was heavily involved in both cup competitions, scoring a try in the home win over Enisei-STM in the European Challenge Cup.