Gallacher, who played rugby for Llanelli and Wales, replaces the Newport Gwent Dragons Chief Executive, Gethin Jenkins, who has stepped down.
The four regions unanimously selected Stuart Gallacher as their represenatative and he took up his new role with effect from 1st June 2009.
He has been associated with Llanelli rugby for more than 40 years, making his debut as a player in 1965 and ultimately taking on the role of Scarlets Chief Executive.
Shortly after his retirement from that role earlier this year he was recruited by all four Regions to act on their behalf in discussions with the WRU.
The Group Chief Executive of the WRU, Roger Lewis, said:”The directors of the WRU play a pivotal role in the union as guardians of our rules of governance.
“Welsh rugby is owned by its member clubs and the board makes sure that their interests are protected.
“Stuart Gallacher has spent a lifetime championing our national sport and undoubtedly has the knowledge, the experience and the passion to make an important contribution.
“I am confident he will act in the best interests of the Welsh Rugby Union at all times and also be a voice for the four Regions on the board with the energy and commitment he has shown in all his rugby endeavours down the years.
“I would also like to take this opportunity to recognise Gethin Jenkins for the important contribution he has made around the boardroom table during his time as a director.
Gethin was a very active board member and he steps down from the board with our thanks and best wishes ”
