The 2011–12 British and Irish Cup was the 3rd season of the annual rugby union competition for second tier, semi-professional clubs from Britain and Ireland.

First round matches began on Wednesday 21 September 2011 and the final was held on Friday 27 April 2012.

[3] Defending champions Bristol had a very poor campaign and were unable to make it out of the pool stages.

Munster A lifted the cup, comfortably defeating Cross Keys 31–12 in the final.

The best four qualifiers (pool winners) had home advantage in the quarter finals.