The 2012–13 British and Irish Cup was the fourth season of the annual rugby union competition for second tier, semi-professional clubs from Britain and Ireland.

The final was contest on 17 May 2013 and won by Leinster A with a 78th minute penalty by Noel Reid to beat Newcastle Falcons 18–17 at their home ground Kingston Park.

The defending champions Munster A were eliminated in the semi–finals by the eventual winners and Bedford Blues was the other losing semi–finalists.

The format of the competition has been considerably revamped, with expansion to 32 teams playing each other home and away in the pool stages.

Pool matches took place on the same weekends as the Heineken and Amlin Cups.