The legendary composer, who recently celebrated his 90th birthday, was joined on stage by a full orchestra, and thanked audiences for “putting magic” into the event.
Williams is the mastermind behind world-famous scores including Star Wars, Jurassic Park and Indiana Jones, the theme tune to which he also played.
For the past four decades John Williams has created the score to our lives
Lucasfilm president Kathleen Kennedy
Following the performance, he was joined by veteran actor Harrison Ford who said it was a “special honour” to be able to wish Williams happy birthday in person.
Ford, who stars in both the Star Wars and Indiana Jones franchises, told the composer the theme to the latter “follows me everywhere I go.”
“It’s a special honour for me to be able to congratulate John on his 90th birthday,” he said.
He continued: “We all know about what John does musically … what I have come to appreciate is the warmth, the generosity, the boyish spirit of this man.
“The wonderful, wonderful talent of this man that we are all blessed with.”
Lucasfilm president Kathleen Kennedy, who also appeared at the opening ceremony, said there were “no words to capture” what Williams’ musical contributions had meant to generations
“For the past four decades John Williams has created the score to our lives,” she said, to cheers from the audience.
Audiences were also treated to multiple teaser trailers to upcoming Disney+ shows and are due to be given an exclusive screening of the first two episodes of the new Obi-Wan Kenobi miniseries on Thursday evening.
Ewan McGregor and Hayden Christensen were reunited onstage to promote the series, with Christensen admitting that there was “nothing like” picking up a lightsabre again.
The Obi-Wan Kenobi panel was introduced by a live choir who sang Duel Of The Fates from The Phantom Menace.
Disney’s Star Wars Celebration takes place at Anaheim Convention Centre, in California, and runs until Sunday.