"Joe's stunning performance in Manchester last weekend was heralded as one of the greatest of all time by a British boxer. It was one of the finest sporting displays ever by a Welsh athlete and the Welsh team wanted to find some way to pay their tribute to Joe," said WRU Chief Executive Steve Lewis.
"We suggested inviting Joe to the game and the players felt it would be appropriate for him to lead them into battle against the Italians. Joe is a hero to all Welsh sports fans and is a constant source of inspiration to fellow professional sportsmen like the Welsh players.
"We have honoured other great sportsmen and women at the Millennium Stadium before, Dame Tanni Grey Thompson joined the team after her great performances at the Olympics and I'm sure the Welsh and Italian fans will give him a rousing reception.
"Joe started his professional boxing career at Cardiff Arms Park when he beat Paul Hanlon in the first round on the Lennox Lewis v Frank Bruno bill on 1st October 1993. Since then he has remained unbeaten in 43 fights, ruled the world for eight years and firmly established himself as one of the all time greats of Welsh and British sport, as well as world boxing.
"While it will be great to have him at the Millennium Stadium as our guest on Saturday, I'm sure I speak for the whole of Wales when I say we are all hoping he might one day return for a world title defence."
Paul Sergeant, Millennium Stadium Chief Executive, added: "Joe is going to add an extra special something to the atmosphere on Saturday. We are delighted he has agreed to lead the team out and, fingers crossed, he will have such a great experience we can entice him back in the summer."