The 1910 Great Britain Lions tour of Australia and New Zealand was the first international tour of the Great Britain national rugby league team, "The Lions". They played the second ever Ashes series against Australia, and their first as the visiting team, before travelling to Auckland to take on New Zealand. The tour was a huge promotional and financial success for what was then known as the "Northern Union" game and helped set the pattern for regular, alternating test match series between Britain and Australia. It is regarded as one of the most important events in the history of rugby league.

The Ashes series, similar to the cricket series of the same name, was a best-of-three series of test matches between Australia and Great Britain national rugby league football teams. It had been contested 39 times from 1908 until 2003 largely with hosting rights alternating between the two countries. Since 1973, Australia has won a record thirteen consecutive Ashes series.