Bolt, 29, won his third gold medal of Rio 2016 – and his ninth overall – as he anchored the Jamaican 4x100m relay team to victory.
He had already said he would be “immortal” if he pulled it off, and after his last ever Olympic race he said: “There you go. I am the greatest.”
He adds the medal to the 100m and 200m golds he took earlier in the Games, just as he did in London and Beijing.
The result was never in doubt as Jamaica’s sprint dream team of Bolt, Asafa Powell, Yohan Blake and Nickel Ashmeade dominated the event, finishing in 37.27secs, around half a second slower than the world record.
But Bolt said the race had not been a foregone conclusion.
“I am just relieved,” he said. “It’s happened. I am just happy, proud of myself. It’s come true. The pressure is real. I look at it as an accomplishment.”
Finally able to relax as his competition ended, he added: “I’ll stay up late tonight!”
Great Britain’s team of Richard Kilty, Harry Aikines-Aryeetey, James Ellington and Adam Gemili finished sixth in 37.98secs after what appeared to be a slow final baton change. Japan took silver and Canada bronze.
After crossing the line, “Lightning” Bolt went on a slow victory lap of the Olympic stadium, enjoying what he has said will be his last ever race at an Olympic Games.
He had claimed before the race that if he achieved the triple triple he would be “immortal”, and few who have witnessed him over the past eight years are likely to disagree.