WRU toast Heineken final.
The WRU beat off an Irish bid from the new Aviva Stadium - the redeveloped Lansdowne Road - to host the 2011 showpiece.
It will be a record sixth time for the final to be staged in Cardiff and the fourth time at the Millennium, with the game pencilled in for the weekend of May 21-22.
WRU group chief executive Roger Lewis said: "This is a great honour for Wales and for Welsh rugby. This event will bring tens of thousands of visiting fans into our capital and create a truly carnival atmosphere for a game which is certain to be a sell-out.
"The three finals staged at the Millennium Stadium in recent years have generated more than pounds 50m for the Welsh economy."
ERC chief executive Derek Mc-Grath added: "Cardiff is a city that has fully embraced the Heineken Cup ever since our first season when the home team reached the inaugural final."
The 2012 final will be played at Twickenham, with the RFU having also beaten off an Irish challenge.