An average of 8.9m people tuned in to watch the live broadcast of the event at London's Wembley Stadium.
Around 63,000 attended the Concert for Diana on what would have been her 46th birthday. The princess died in a car crash in Paris in August 1997.
Sir Elton John, Lily Allen and Duran Duran were part of the line-up.
Charitable causes
Sir Elton, 60, opened the concert with a rendition of Your Song performed in front of a giant image of Diana.
The singer closed the event, which saw performances from an array of international stars, with Saturday Night's Alright for Fighting and Tiny Dancer.
Hosts Prince William and Prince Harry, who introduced Duran Duran at the beginning of the concert, returned to the stage at the end of Sir Elton's final set, praising the artists for an "incredible evening".
Proceeds from the event, broadcast to 140 countries, willl go to charitable causes favoured by the princess.
Video tributes from ex-South African President Nelson Mandela, the former Prime Minister Tony Blair and ex-US President Bill Clinton were broadcast during the gig.