Davies, 60, unseated Howard Watkins, the long-serving committee and board member, and also held off competition from former Wales and Lions team-mate JPR Williams and Newtown official Dai Davies.
WRU chairman David Pickering won re-election by a substantial majority and the pair will act as the board's national representatives for the next three years.
Pickering said: "I'm obviously delighted that my leadership has been given such a vote of confidence by the membership, although I also see it as an endorsement of the way in which the board and the executive officers have performed in recent years.
"It is a great shame to lose Howard Watkins. He has worked tirelessly for the good of Welsh rugby during his time as board member and I would like to thank him for his contribution.
"It will be good, however, to welcome such a world renowned rugby man as Gerald Davies onto the board.
"In his letter to the clubs he said that he wanted to make a contribution to the game and I'm sure he will prove a major asset to us."
Davies had declared in his letter of intent, which was sent to all the voting clubs: "I want to be part of forging a sound Welsh rugby future."
Pickering polled 179 votes from the clubs with Gerald Davies 126, Watkins 83, Williams 34 and Dai Davies 26.
Pickering's re-election was no surprise at all given he has presided over a period which has seen Welsh rugby transformed both on and off the field.
The WRU, which only two years ago recorded losses of Â£3.7million, announced record profits of Â£3.6million in June this year.
The results were driven by Wales' Grand Slam triumph and the development of the Millennium Stadium as a multi-purpose venue.
Pickering said at the time: "Welsh rugby was a winner on the field in the Six Nations, but the good work off the field of everyone involved in our national sport and our national stadium has helped us to deliver record profits for the WRU Group.
"The success of the national team was a huge catalyst for our financial improvement.
"With seven home games to look forward to at the Millennium Stadium next season including three home games in the Six Nations and the mouth-watering prospect of showdowns with the three Tri-Nations countries in November, there is every likelihood of an even better financial return over the next 12 months."