The 2005 Twenty20 Cup Final was a cricket match between Somerset County Cricket Club and Lancashire County Cricket Club played on 30 July 2005 at The Oval in London. It was the third final of the Twenty20 Cup, which was the first domestic Twenty20 competition between first-class sides. It was the first occasion on which either side had reached the final; Lancashire had reached the semi-finals in 2004, but for Somerset it was the first time they had progressed further than the group stage of the competition.