The "Tiny Dancer" singer was one of a handful of celebrity guests invited into Westminster Abbey inLondon to see the royal couple wed, and as he watched the union, he appeared almost moved to tears.
Elton was sat next to his husband, David Furnish, in the front row of the Abbey for the proceedings. The singer was aclose friend of William's mother Diana, and performed at her funeral after her death in a carcrash in 1997.
Other celebrities among the wedding's 1,900 guests included soccer star David Beckham and his wife Victoria, invited after David worked closely with the prince on England's bid to host the 2018 World Cup.
The couple described the ceremony as "beautiful and heartfelt," before adding to BBC News: "Catherine looked wonderfully elegant, and we were honored to be part of such a special, historical day for our country.
"We wish Catherine and William much love and happiness for the future."
Also in attendance at the wedding were film director Guy Ritchie, actor Rowan "Mr. Bean" Atkinson, and singer Joss Stone.
Many celebrities took to Twitter to pay their respects to the happy couple, including singer George Michael, who had recorded a version of Stevie Wonder's track "You and I" as a present for the couple.
During the wedding service he tweeted: "One word... Class (sic)."
Model and actress Kelly Brook admitted the wedding stirred her emotions, tweeting: "I cried all the way through!! I cried when they opened the doors to WestminsterAbbey!! Stunning (sic)."
"California Gurls" singer Katy Perry decided to pay her own tribute by decorating her nails with different pictures of William and Kate.
She posted the picture with an accompanying tweet reading: "In honor of the Royal Wedding, I present you... My royal NAILS! CONGRATS (sic)."
Former Spice Girls singer Emma Bunton also wished the couple well, writing: "Absolutely beautiful couple!!! They look exquisite!"
