The former Wales captain and team manager David Pickering, a National Representative on the general committee, becomes vice-chairman in place of the now retired Les Williams.
Mr Griffiths followed Vernon Pugh into the chair in September, 1997. Mr Pugh, who is now chairman of the International Rugby Board,was the Union’s inaugural chairman, a post he held for four years.
At last month’s Annual General Meeting, Mr Griffiths was appointed as the Union’s Honorary Treasurer for a 19th term. He is also chairman of Millennium Stadium plc.
“The next 12 months are vital for the future of Welsh rugby. The clubs have given the go-ahead for huge changes in the way in which our game is run and governed and I intend to drive this process forward to ensure there is as seamless a transition as possible,” said Mr Griffiths.
“We are working hard on the finances of both the Union and the Millennium Stadium, while on the field Steve Hansen and his coaching team have a World Cup in their sights.
“It all adds up to an incredibly important period in the history of Wales’national sport, especially as we will be nominating our new Group Chief Executive in the autumn, and I look forward to meeting all the challenges that lie ahead next season.”