The Wales men’s national rugby union team (Welsh: Tîm rygbi'r undeb cenedlaethol Cymru) represents Wales in men's international rugby union. Its governing body, the Welsh Rugby Union (WRU), was established in 1881, the same year that Wales played their first international against England. The team plays its home matches at the Millennium Stadium in Cardiff (currently known for sponsorship reasons as the Principality Stadium), which replaced Cardiff Arms Park as the national stadium of Wales in 1999.

Wales has competed annually in the Six Nations Championship (previously the Home Nations Championship and Five Nations Championship) since it was established in 1883. They have won the tournament (and its predecessors) outright 28 times, most recently in 2021. Since the Six Nations was formed in 2000, Wales have won six Six Nations titles, including four Grand Slams and finished bottom once. Wales has also participated in every Rugby World Cup since the competition was established in 1987; they finished third in the inaugural tournament and have since made two semi-finals, in 2011 and 2019. Wales were the host nation for the 1999 Rugby World Cup, although matches were also played in England, Scotland, Ireland and France.

The Wales team experienced their first 'golden age' between 1900 and 1911; they first played New Zealand in 1905, winning 3–0 in a famous match at Cardiff Arms Park, and between March 1907 and January 1910, they won 11 consecutive matches, a record that stood for over a century. Welsh rugby struggled between the two World Wars, but experienced a second 'golden age' between 1969 and 1980, when they won eight Five Nations Championships. In addition to their Six Nations successes, Wales also finished fourth at both the 2011 Rugby World Cup and 2019 Rugby World Cup. Additionally Wales won 14 consecutive matches between March 2018 and March 2019, and reached number 1 in the World Rugby Rankings for the first time in August 2019. Eight former Welsh players have been inducted into the World Rugby Hall of Fame; 10 were inducted into the International Rugby Hall of Fame prior to its 2014 merger into the World Rugby Hall of Fame.