Born in Wales to a Welsh mother and English Londoner father, Warburton has represented Wales at all levels, including being captain of the U18s, U19s and U20s. He led Wales to the under 19s and under 20s World Cup semi-finals.

Warburton made his debut for the senior Wales national rugby union team on 6 June 2009 versus the USA. He scored his first international try against Italy in the 2011 Six Nations tournament.

Warburton made the highest number of turnovers at Rugby World Cup 2011, and despite his red card in the final, was named player of the tournament.