The American safely crossed the line in the peloton at the end of the 144.5-km final stage on the Champs Elysees.
The last climb in his career was to the podium, on which he stood next to second-placed Italian Ivan Basso and the rider he beat most often, Germany's Jan Ullrich.
The most successful Tour rider in history looked to the sky while the Star Spangled Banner was played for him for the seventh and last time.
Points classification winner Thor Hushovd of Norway and Denmark's King of the Mountains Michael Rasmussen brought a Nordic touch to the Texan's farewell ceremony.
Ukraine's Yaroslav Popovych, sporting the white jersey as the best under-25 rider in the Tour, gave hope to Armstrong's Discovery Channel team mates that the yellow jersey might stay with them next season.
Kazakh Alexander Vinokourov won the final stage of the race after making a break on the last lap on the Champs Elysees.
Armstrong's final Tour was arguably one of the easiest for him, even if the 33-year-old had to be content with winning only one stage, Saturday's 55.5-km individual time trial in St Etienne.
It seemed impossible in 1999, when he collected the first of his 82 yellow jerseys and the third of 23 stage wins, for anyone to win seven Tours -- in particular a rider like Armstrong who almost lost his life to testicular cancer diagnosed in 1996.
In the seven years that ended on Sunday, Armstrong helped cycling shift from a sport of traditions and folklore into a modern, professional, global one.
His final Tour was among the easiest simply because nobody really dared contest his supremacy.
Armstrong's compatriot David Zabriskie wore the yellow jersey at the beginning of the race and then German Jens Voigt took it for a day.
There were vain, sometimes embarrassing attacks from Ullrich's T-Mobile team mates, there were brave moves from Basso, the American's likeliest successor, but by and large, Armstrong spent a rather relaxing three weeks on French roads.
Whereas former Tour greats Jacques Anquetil, Bernard Hinault and Miguel Indurain mostly built their victories in time trials, Armstrong, like his close friend Eddy Merckx, dominated on all terrains.
Armstrong was the fastest against the clock -- as the last victory of his career in St Etienne confirmed -- the strongest in the mountains and he led the best team.
His attention to detail and obsession with the Tour are well known but his pure sporting skills and extraordinary strength of character are often overlooked.
Like Merckx, Hinault or Anquetil, Armstrong was not interested in being a popular rider. His only goal was to win the Tour.
Only three men seriously challenged his domination -- Italian climber Marco Pantani, Basque rider Joseba Beloki and Ullrich.
Pantani was the only rider able to outclass Armstrong in the mountains and their private battle in 2000 was one of the highlights of the American's Tour campaigns. Pantani committed suicide in February last year.
Beloki improved with every year until the 2003 race when he crashed in front of Armstrong and suffered multiple fractures. The spectacular fall destroyed the Spaniard's ambitions and he has still not made it back to the same level.
Ullrich was Armstrong's favourite opponent. When the German won the 1997 edition, everybody was convinced he would be the first rider to win six Tours.
He had class, power and no other active rider at the time -- Armstrong was having treatment for cancer -- seemed a serious contender.
Eight years later, the 32-year-old has had to be content with one Tour, one Vuelta, one Olympic gold and two world titles, plus six podium places in the Tour.
Ullrich's career has been great, not exceptional because he had the misfortune of riding in Armstrong's time.
With no chance of an encore from Armstrong, cycling fans are now looking for the next Tour winner.
Basso, who finished four minutes and 40 seconds behind Armstrong overall, is arguably the most versatile of all potential Tour winners. Ullrich cannot be ruled out if next year's Tour places more emphasis on time trials.
Spain's Alejandro Valverde, winner of the toughest Alps stage in this Tour, is also cited as one to watch.
But the winner will triumph in a race that can never be the same again, because of the man who retired on Sunday.