The stars are a familiar pairing, having played Glinda and Fiyero in the recent film adaptation of Wicked and its sequel, For Good.
Their performances cemented their places as two of Hollywood’s hottest properties, with Ariana earning an Oscar nomination last year.
But they’ll hope to have theatre audiences under their spell when they swap Oz for London.
Sunday in the Park with George was inspired by French painter Georges Seurat’s A Sunday Afternoon on the Island of La Grande Jatte, in which a fictional version of the artist is consumed by his work.
The character, fixated by a particular hat in his painting, sings “all it has to be is good”, the lyric quoted in the co-stars’ Instagram caption.
While their roles are unconfirmed, the musical’s female lead is Dot, Georges’ lover.
The pair grow apart as Georges’ attachment to his art becomes more and more fierce.
Ariana will already spend part of 2026 in London as she has 10 dates scheduled for The O2 across August and September as part of her Eternal Sunshine Tour.
Last November, she warned fans it’s likely to be her last tour for a “long time”, but her post with her Wicked co-star suggests she’s not stepping off-stage altogether.
BBC Newsbeat has approached the Barbican Theatre for comment.