Prince William, who is the WRU’s Vice Patron, presented Mr Gethin with the honour at a ceremony in London.
The WRU president, who was appointed in 2007, was named in the Queen’s 90th Birthday Honours list in June.
Now living in Pontypridd, Mr Gethin was a first class full back in his playing days, obtaining two Rugby Blues while at Cambridge and representing his home club of Severn Sisters before going on to play for Swansea , Neath , Cardiff and Glamorgan Wanderers before giving up rugby to concentrate on his legal career.
As well as being the former Taff Ely Borough council’s chief executive, he was Secretary of the Welsh Rugby Union between 1998 and 2003, overseeing the construction of the Millennium Stadium and the 1999 Rugby World Cup.
But he says it’s his role as WRU president, and association with the Welsh Rugby Charitable Trust, that have been most enjoyable.
“It is a great honour and I have so many people to thank, especially the grassroots clubs,” said Mr Gethin, who is also president of the Welsh Rugby Charitable Trust for injured players.
“Everyone in Welsh rugby has been so helpful throughout my career but my time as president has certainly been most rewarding and I owe this accolade to Welsh rugby clubs, and to the Welsh Rugby Charitable Trust.
“I must also thank my wife Janet, who has been a superb help to me throughout this time.”
Mr Gethin also holds the posts of president Wales Deaf Rugby, chairman Welsh Rugby Charitable Trust, a charity dedicated to providing help and support to severely injured rugby players, patron of Glamorgan County Rugby, life member of Welsh Academicals RFC and Seven Sisters RFC, president Cor Meibion Pontypridd and vice president Cor Meibion De Cymru.
WRU chairman Gareth Davies said: “Dennis is thoroughly deserving of this honour, he is totally committed to Welsh rugby at all levels.
“He makes an ideal president as he truly represents all facets of Welsh Rugby, having played the game at the top end, administered the Welsh Rugby Union and through his commitment to grassroots clubs and work with the Welsh Rugby Charitable Trust.”
