The Wales national under-20 rugby union team is for Welsh rugby union players aged 20 or under on 1 January of the year during which they are selected. Under-20 age grade rugby came into existence as a result of the IRB combining the Under 19 Rugby World Championship and Under 21 Rugby World Championship into a single IRB Junior World Championship tournament. They also compete in the Six Nations Under 20s Championship.

Six Nations Under-20 Championship

Wales finished second in the 2008 tournament, losing only to England. In 2013 Wales were denied a Grand Slam in their final match against England, and ultimately placing second on points difference. Wales finally achieved a Grand Slam and their first U20 title in 2016, defeating Italy on the final week 35–6, having been level 6–6 at half time. They also secured their first Triple Crown at this age group. In 2023, the side did not win a single match, leading to their first winless tournament of the U20 era. Ahead of the 2024 Six Nations Under 20s Championship, Richard Whiffin was named as head coach, replacing Mark Jones who joined the Ospreys.

Junior World Championships

In June 2008 Wales hosted the 2008 IRB Junior World Championship. As hosts they played all their group matches at the Liberty Stadium in Swansea, starting against Italy on Friday 6 June, before further ties against Japan and France. Wales won all three group matches before losing the semi-final to New Zealand and subsequently losing the 3rd place play-off to South Africa. For the tournament the same management team remained from the 2008 U20 Six Nations; head coach Patrick Horgan and assistant coaches Rob Appleyard and Wayne Jones. Sam Warbuton remained as captain. For the next two Junior World championships, Wales alongside France will have to start the pool stages with a three-point deficit, following a brawl between the two sides in the 2008 tournament. At the 2010 IRB Junior World Championship the Welsh squad won 2 games in the preliminary round against Samoa and Fiji while losing to New Zealand. At the playoffs for the 5th–8th place they first drew with Argentina 19–19 but lost in a drop goal shootout 9–8 and then met Fiji for a second time, again winning by 39–15 to finish in 7th place. In 2011, after winning their opening game 34–8 against Argentina they were on the receiving end of a 92–0 thrashing by New Zealand in Italy, a record defeat for the side. In 2012 Wales beat New Zealand 9–6, the first time the Baby Blacks have ever been defeated in the competition. This was also the first Welsh win against New Zealand at any level since 1954. However, later in the tournament Wales lost 30-6 to New Zealand in the semi-final. 2013 was the side's most successful year, making it to the final, where they faced England. Wales lead 15–3 at half time, but ultimately lost 23–15. Ahead of the 2023 Junior World Championship, former international wing Mark Jones was appointed as head coach, replacing Byron Hayward.

Players

Current squad

Head coach Richard Whiffen named a 37-man squad for the 2024 Six Nations Under 20s Championship.

Award winners

The following Wales U20s players have been recognised at the World Rugby Awards since 2008:

Management

Results and statistics

Honours