During Edwards' era, Wales won seven Five Nations titles, including three grand slams. He also starred for the British Lions on their winning tours of New Zealand in 1971 and of South Africa in 1974.
But possibly his most famous moment came when he finished off a length-of-the-field try for the Barbarians against the All Blacks in 1973 at Cardiff Arms Park.
Amongst his many varied engagements, Gareth is a Non-Executive Director of Cardiff Blues and Chairman of Future Blues the regional rugby development scheme.
Speaking on Radio Wales, he said: "I couldn't believe it. I read [the letter] about three or four times. I thought they'd sent it to the wrong person.
"When this kind of recognition does come along you are just flabbergasted but delighted with the whole thing.
"You don't do it for the recognition. You're just delighted that somebody actually does write you and say you've made a great effort thank you very much."
Welsh Rugby Union chief executive Roger Lewis, paying tribute, said Edwards was an "icon" in the game.
"Since finishing playing he has continued to hit the headlines with his work in business and charity and a CBE is just reward for his continued contribution to Welsh life," he said.