The tribute has been bestowed to signify the unique way he crossed the well trodden divide from player to broadcaster and added to the reputation of Wales and our national sport.
The WRU decided the press conference room, where the worlds of rugby and journalism meet, was the ideal location for a tribute to the former Scarlet who died in 2007 aged 56.
Thousands of visitors to the Millennium Stadium will visit the room as part of the official guided tours which take place throughout each year.
Ray's widow Mari and their daughters Manon and Gwenan visited the Ray Gravell Room today (Saturday 7 November) to unveil the refurbished facility.
The room was formally opened by the Welsh Rugby Union President, Dennis Gethin, who headed up a WRU committee to plan the tribute. The Ray Gravell Room contains fourteen different wall mounted photographs of his life as a player for Llanelli, Wales and the British and Irish Lions along with his work as a broadcaster in English and Welsh.
Dennis Gethin said: "We are proud to be able to honour a man who gave so much to Wales and its people during his lifetime. He epitomised the true meaning of the word, ambassador, and championed the story of Wales, its culture, its heritage and its sporting traditions wherever he went.
"His success was based on his humanity and the standards of respect and honour he epitomised throughout his life and within all his endeavours. His memory deserves special recognition because he earned himself an important place in the social history of modern Wales as a true voice of the nation.
"Like so many people I am proud to have been able to call him a friend and I am delighted that Mari and their daughters, Manon and Gwenan, are able to join in this celebration of a wonderful man."
Ray Gravell won 23 Welsh caps and played in four British and Irish Lions test matches during a playing career in which he was also the youngest player in the Llanelli team which defeated the New Zealand All Blacks, 9-3, in 1972.
After retiring from the game in 1985 he became a broadcaster working mainly in sport but he also developed as an actor in films such as Rebecca's Daughter which starred Peter O'Toole and Damage with Jeremy Irons.
Mari Gravell said: "As a family we are proud and delighted that the Welsh Rugby Union is honouring Ray in this way.
"He was passionate about his support for rugby and he was extremely proud of the links he maintained with the sport through his work as a broadcaster. It is lovely to think that Ray's memory will live on in this formal way within the stadium where he spent so much of his working life and enjoyed being part of so many wonderful rugby moments."
The Chairman of the Welsh Rugby Union, David Pickering, said: "The naming of a room after Ray at the Millennium Stadium is a fitting tribute to a wonderful man. I played alongside him for Llanelli and I was just 19 when he appointed me as his vice captain of that side. I also played in the same Llanelli team as Ray against Graham Mourie's All Blacks in 1980 so I have many fond memories of him as a wonderful friend and teammate.
"So many people share pleasant and positive memories of Ray and I think much of that is because he was such a genuine human being who possessed all the qualities which go to make a special person. He made his mark on sport in Wales, on the world of broadcasting and he certainly won over and impressed whoever he met around the world." "
The Group Chief Executive of the Welsh Rugby Union, Roger Lewis, added: "Ray Gravell played significant roles in two fields of expertise which feature powerfully in the story of this Millennium Stadium.
"He was part of its fabric throughout its ten year life and has written his own chapter in its iconic history. The values he epitomised were a virtual mirror of the values which are enshrined in our national sport.
"I am pleased that through this tribute to Ray future generations will learn valid lessons of the importance of remaining true to the values which dignify us all."