His three-year term of office begins with immediate effect and will run alongside his current role as WRU chairman - a role he has fulfilled during two Grand Slam victories for the senior Wales side and which has coincided with the changeover to professionalism in rugby and seen him steer the Union through a £30 million overall reduction in debt.
He is a former Wales captain who won 23 caps between 1983 and 1987 before retiring to take up coaching and team management. He was Wales team manager from 1998 until 2001 when the team went on it's record 10-match winning streak under then coach Graham Henry.
He is also Chairman of the board of the Millennium Stadium and was elected to be a National representative of the Welsh Rugby Union in 1998 and became Chairman of the Union in 2002. He joined the IRB Council in 2000.
He said: "I am proud and honoured to have appointed to this role. The RBS Six Nations tournament is the most successful annual international rugby competition in the world and I am looking forward to ensuring it continues to thrive and develop.
"Here in Wales the Six Nations is part of our rugby culture and I am delighted to have been given the chairmanship as we are celebrating yet another Grand Slam victory.
"My colleagues on the committee are all great ambassadors for their countries and I am looking forward to building on the work we have already achieved."
WRU Chief Executive Roger Lewis added: "David's appointment is fantastic news for Welsh rugby, he is one of the most respected administrators in the world game and it is with great pride that we welcome his appointment to such a high office.
"The fact that he has been chosen for this new honour just goes to show the calibre of the man we have in our midst. He will continue to represent Wales at the very highest of levels in the world game and the WRU can only benefit from the commitment and service he can offer to rugby in the years to come."