He amassed 43 Lions appearances, including nine at Test-match level, and won a further 37 caps for Ireland before ending his international career in 1970.
Although a specialist tight-head, Millar played both Tests against the Wallabies in 1959 as loosehead and was the most-used prop on his first tour to South Africa three years later.
A fly-half during his junior days, the former Ballymena front row forward went on to coach his country at the inaugural World Cup in 1987 before serving as a popular Chairman of the International Rugby Board (IRB) until 2007.
Millar was awarded France's highest decoration, the Légion d'honneur, at a ceremony by Bernard Lapasset, his successor as IRB Chairman.
Syd Millar's factfile
Date of birth: May 23 1934
International caps: Ireland 37
Height: 6ft (1.83m)
Weight: 16st (102kg)
Millar's Lions lowdown
Lions debut: Versus New South Wales, May 30, 1959
Lions Tests: 9 (Both Tests vs Aus and 2nd Test vs NZ in 1959, all four Tests against SA in 1962, 1st and 2nd Tests vs SA in 1968)
Lions non-Test appearances: 34
Total Lions appearances: 43 (18 in 1959, 16 in 1962 and nine in 1968)
Lions points: 10* (two tries) *under the current scoring system of five points for a try
Final Lions appearance: Versus Orange Free State, Bloemfontein, July 20, 1968
Syd Millar at the 2007 Rugby World Cup in his role as outgoing IRB Chairman
On touring South Africa
"South Africa is a great place to tour and on the High Veld, with their dry, hard grounds, it is a super place to play a handling game, while the huge public interest makes it something special - only New Zealand matches them for their enthusiasm and commitment to the game.
"To some degree it is hard to differentiate between playing and coaching but all four of my trips to South Africa were really good tours.
"I guess the 1962 tour was a good trip as a player, when we drew the first Test, lost the second 3-0 and the third on a mistake. It was a close series and perhaps we deserved a bit better.
"In 1968 we didn't have the same capacity of players but we did OK and in 1974 as coach we didn't lose a game - winning 21 and drawing one out of 22 matches and playing some great rugby along the way.
Millar is a truly legendary Lion and one of rugby's greats
On the spirit of the Lions
"Attitude is the first thing a team needs to have. If the attitude is right, the other things fall into place.
"You will always have guys who are disappointed when they don't get in the Test side. They may be star players in their own country but they could be only number three in their position in these islands. Those guys can turn off a bit.
"The second team is very important on Lions tours; it's vital they keep their side of the tour up. The captain has to make sure those guys know how important they are to the team and to the final result."
On the unique qualities of a Lions captain
"The captain has to be a psychologist because the players are all different.
"Some don't like being away from home, for example, so the captain has to identify that and spend some time with them. Even though tours are now down to six weeks, that is still a long time compared to national tours today, which are just a few weeks.
"Others lack confidence. It's a big deal going on a Lions tour, especially for young players, and the captain has to make sure everyone feels involved.
"Sometimes it can be simple things like receiving letters. There was one player like that in 1974 and we made sure we didn't hand out any letters until his had appeared.
"The main difference between captaining the Lions and captaining your country is of course that the captain has to unite four different sets of players. To do that, he has to be a motivator and a leader of men.
"The captain has to develop that pride in the Lions.He has to have the respect of the players, so you want to be sure the captain will hold his place in the team. That's not absolutely critical but it's very, very important.
"I made Willie John McBride Irish captain and I made him Lions captain too. He was my choice because I knew how he thought and he knew how I thought so it wouldn't take long to get us working together."