Since then, the musical adaptation of the hit film has become a global phenomenon that has delighted fans from Sydney all the way to Broadway.
So to celebrate the fifth anniversary of the popular show, celebrities joined 19 past and present 'Billys' at the Palace Theatre in the British capital this week for a very special performance.
Heading up the festivities was iconic performer Elton John, who wrote all the music for the production, and his long-term civil partner David Furnish.
The 63-year-old composer took to the stage during the evening to speak of his pride in the musical, which has picked up four Laurence Olivier awards and a Critics Circle gong.
And while it is his name attached to the project, Elton paid tribute to his partner David, who he said, suggested Billy Elliot would make a "great musical" when the pair first watched the film in Cannes in 2000.
"I stole all the glory," the talented pianist joked before adding: "It's a remarkable show with a life of its own."
Meanwhile, Stephen Daldry, who directed both the stage and film versions, admitted that he didn't know whether the musical would be a hit.
"When we first started performing this show I really didn't think we would get through the end of the week," he confessed.
Among those watching the show, which saw all the 'Billys' perform together for the first time during the curtain call, was David Walliams and his fiancée Lara Stone, as well as the original run's adult stars Tim Healy and Haydn Gwynne, who played Billy's father and ballet teacher respectively.