Founder Michael Eavis had previously said the fate of the 2021 event was uncertain as this year’s festival was cancelled because of coronavirus.
His daughter Emily said: “We’re still very much aiming for June.”
The 2020 festival would have been a 50th anniversary celebration and 135,000 music fans who bought tickets will be able to use them next summer.
“For those who have been asking, we have no plans to move next year’s G to September 2021 – we’re still very much aiming for June,” she said on Twitter.
She said there will be no ticket resale in October because “so few people have asked for a refund, meaning we don’t have enough tickets to resell”.
The resale has instead been pushed back to April 2021 and the free cancellation deadline moved until the end of January 2021.