Beckham, who was instantly dropped when McClaren inherited the England job from Sven-Goran Eriksson in 2006, is to quit the game at the end of the season.
He bows out as a Ligue 1 winner with Paris St Germain, with the 38-year-old deciding the time is right to step away from his illustrious playing career.
Beckham eventually won over McClaren in their England days, earning a recall.
And McClaren said today: "He was a great player.
"He made the very most of his talents through sheer hard work and professionalism and always doing extra work on the training field.
"He inspired his team-mates through his performances.
"He was a winner, he's won so many things in his career, and that was infectious on his team-mates.
"And he was an inspiring personality to young players with his behaviour and professionalism on and off the field.
"But ultimately he was a leader and people followed him.
"The young players followed him in how he played and in his personality, and even off the field the young players of today are following him through his fashion."
McClaren told Sky Sports News: "By the end of his career he was a fantastic ambassador, not only for football around the world but for our country as well in helping bring major events to this country."
Beckham had a role in bringing the Olympic Games to London, but it will be his footballing feats for Manchester United, Real Madrid, PSG, LA Galaxy and AC Milan for which he will be remembered.
"He has been very special in that right midfield position," McClaren said.
"He was an unbelievable passer, crosser of the ball, and he could score goals as well.
"My lasting memory of David Beckham is him continuously being the last off the training pitch and always practising those trademark free-kicks."
Beckham won 115 caps for England, more than any other outfield player.
But on the big stage, England repeatedly struggled to achieve, falling in quarter-finals at World Cups in 2002 and 2006 and Euro 2004.
"Because he was a big part of that, he was very frustrated by that," said McClaren.
Beckham added: "If you had told me as a young boy I would have played for and won trophies with my boyhood club Manchester United, proudly captained and played for my country over one hundred times and lined up for some of the biggest clubs in the world, I would have told you it was a fantasy. I'm fortunate to have realised those dreams."
Beckham made his debut for Manchester United in 1992, winning six league titles and the Champions League before moving to Real Madrid and Los Angeles Galaxy, plus loan spells at AC Milan.
He made his England debut in 1996 and would go on to be the Three Lions' most capped outfield player with 115 appearances. He was the first English player to score in three consecutive World Cup finals tournaments.
Beckham said: "To this day, one of my proudest achievements is captaining my country.
"I knew every time I wore the Three Lions shirt, I was not only following in a long line of great players, I was also representing every fan that cared passionately about their country. I'm honoured to represent England both on and off the pitch."
Beckham won the Primera Division title in his final season in Spain and the US Major League Soccer championship twice.
He added: "I wouldn't have achieved what I have done today without my family. I'm grateful for my parents' sacrifice, which made me realise my dreams. I owe everything to Victoria and the kids, who have given me the inspiration and support to play at the highest level for such a long period. I also want to thank Simon Fuller and his team for their continued support.
"I want to thank all my team-mates, the great managers that I had the pleasure of learning from. I also want to thank the fans who have all supported me and given me the strength to succeed."
Beckham has this year become an ambassador for the sport in China.
"Nothing will ever completely replace playing the game I love, however I feel like I'm starting a new adventure and I'm genuinely excited about what lies ahead," said Beckham.
"I'm fortunate to have been given many opportunities throughout my career and now I feel it's my time to give back."
Beckham has two final games before the end of the season, the last home match of his career being this Saturday against Brest at Parc des Princes.
FA chairman David Bernstein paid tribute to Beckham.
He said: "In the week following Sir Alex Ferguson retiring, which came as a bit of a shock, now we have the iconic David Beckham coming out of the game.
"It's unexpected even though he is getting to mature years for a footballer.
"He is an iconic figure in the game and produced wonderful performances for his clubs, particularly Manchester United.
"When you look at his playing and work for England, no one would ever accuse him of being unpatriotic and not giving everything for his country.
"He is a real loss to the game and I am sure the FA will want to embrace him and to get him closely associated with the organisation.
"I would personally wish him every luck and success - he will be quite a loss to the game."
Sven-Goran Eriksson, whose tenure as England manager between 2001 and 2006 coincided with some of Beckham's best years, not to mention his captaincy, told BBC Radio Five Live: "He is a fantastic footballer and a fantastic person. All over the world you say 'David Beckham' and people know who that is.
"I don't think any other football player is more popular than he."
Meanwhile, a Downing Street spokesman gave Prime Minister David Cameron's verdict.
''The Prime Minister's view is that David Beckham has been an outstanding footballer throughout his career, but not only that, he has been a brilliant ambassador for this country, not least if we remember all the work he did on helping us win London 2012," said the spokesman.
''The Prime Minister's message would simply be to say: congratulations on a fantastic career.''
AC Milan, who signed Beckham twice on loan during the Major League Soccer off-season, posted a statement of thanks to the player on their official website.
The club acknowledged that his initial arrival was not universally deemed to be good business, but praised his contribution at the San Siro.
"His arrival at the club may have been greeted with some skepticism but his performances as a player quickly won over the non-believers," it read.
"Two goals against Genoa and Bologna as well as 29 appearances with AC Milan helped the team towards two Champions League qualifications.
"Thank you and good luck from all the fans and everyone at the club to David Beckham."