The 1910 British Lions tour to Argentina was a rugby tour of Argentina made by a side made up of 16 English players and 3 Scots. The organisers of the tour named the team the "English Rugby Union team", but the host country advertised the touring team as the British Combined. The 1910 team has been termed as one of the three "lost lions" tours, and is detailed on the British and Irish Lions official website. For Argentina, this tour marked the start of international rugby union and the test against the Combined British on 12 June 1910 was the first test in the Argentine national team's history.

The British & Irish Lions is a rugby union team selected from players eligible for the national teams of England, Ireland, Scotland, and Wales. The Lions are a test side and most often select players who have already played for their national team, although they can pick uncapped players who are eligible for any of the four unions. The team tours every four years, with these rotating between Australia, New Zealand and South Africa in order. The most recent test series, the 2021 series against South Africa, was won 2–1 by South Africa.