The 2006 Heineken Cup Final was a rugby union match played at the Millennium Stadium in Cardiff, Wales, on 20 May 2006, to determine the winners of the 2005–06 Heineken Cup, European rugby's premier club competition. The match was contested by Irish province Munster and French side Biarritz. It was the 11th Heineken Cup final overall and the third final appearance for Munster, while Biarritz were competing in their first final. It was the second time the Millennium Stadium had hosted the Heineken Cup final, the other being in 2002, and the fourth to take place in Cardiff, including finals played at the old Cardiff Arms Park.

Biarritz Olympique Pays Basque, usually known simply as Biarritz, is a French professional rugby union team based in the Basque city of Biarritz, Nouvelle-Aquitaine which competes in the Pro D2, the second division of French rugby. Biarritz plays its home matches at the Parc des Sports Aguiléra, which is a multi-use stadium in Biarritz and which has a capacity of around 13,500 people, though for games that need a larger capacity, Biarritz may play at the Estadio Anoeta in San Sebastián. Biarritz play in red and white colours. Biarritz won a number of major honors, including the French championship on five occasions.