On Friday the festival announced more than 50 other acts for its 2023 line-up, with hundreds more expected to be added in the coming months.
Yusuf/Cat Stevens will perform during the tea time legends slot on Sunday afternoon, despite Roxy Music being heavily rumoured, the BBC said.
The veteran folk-rocker, best known for a string of albums in the 1970s, follows in the footsteps of artists such as Dolly Parton, Kylie Minogue and Diana Ross.
The initial wave of acts includes Christine And The Queens, Lana Del Rey, Lewis Capaldi and Lil Nas X.
Also slated to perform are Loyle Carner, Rudimental, Slowthai, Thundercat, Fatboy Slim and Young Fathers.
Arctic Monkeys, who recently released their seventh album The Car, will close the Pyramid Stage on Friday night – their third time topping the bill.
Saturday night will see US rockers Guns N’ Roses headline, after the original line-up of Axl Rose, Slash and Duff McKagan reunited in 2015.
Lizzo will play immediately before and has joint headline billing on the line-up poster.
However, the acts closing the Pyramid Stage throughout the festival will be all-male.
Co-organiser Emily Eavis told the BBC she aimed for gender balance and this year they had a female headline but “she unfortunately had to pull out”.
She added: “It changes all the time. But next year it’s looking like we’ve got two female headliners, so fingers crossed.”
Taylor Swift was confirmed as a headliner for the cancelled 2020 festival and there had been speculation she could have headlined this year.
Nigerian Afrobeats star Wizkid will headline the Other Stage, the festival’s second largest, on Friday night, while Del Rey will feature on Saturday.
Christine And The Queens will top the bill on the Woodsies Stage, previously called The John Peel Stage.
Eurovision winners Maneskin will make their debut at the festival, as will Brits Rising Star winners Flo.
Sir Elton’s headline slot on Sunday night is expected to draw large crowds, as it marks his final UK show of his farewell tour.
His ongoing 300-plus date worldwide tour will usher in his retirement from touring after 52 years on the road.
Eavis told the BBC securing Sir Elton as the festival’s closing act on the Sunday night was a “massive, massive coup”.
She added: “And he’s really up for it. He’s been on the phone with loads of brilliant ideas and he’s just fired up about it.”
Tickets for the event are sold out but there will be a re-sale of any cancelled or returned tickets in Spring 2023 for those who missed out.
The 2023 event will run from June 21 to 25 at Worthy Farm in Somerset.