The 27-year-old Australian actress and producer stunned onlookers in her floor-length ensemble with its pink hue and vivid design from Versace's Spring 2018 collection. It centres around the creation of iconic children's story Winnie The Pooh and the life of its creator, AA Milne.
The actress cut a summery figure in her flowing baby pink dress with a low-cut neckline that emphasized her toned figure.
She complimented the look with natural, rosy make-up to let the unique number speak for itself and wore her blonde locks in a short, flicked-out bob style with a side-parting.
Joining Margot at the screening were her co-stars, Domhnall Gleeson (who plays A.A. Milne), Will Tilston (who plays young Christopher Robin), and Kelly Macdonald (Olive).
And her flawless complexion radiated with blush, nude lips, and earthy eye shadow.
The site's critical consensus reads: "Goodbye Christopher Robin struggles to balance wartime tension and childlike wonder, but offers valuable insight into the darkness shadowing the creation of a classic children's tale".
Directed by Simon Curtis (Woman in Gold, My Week with Marilyn) and written by Frank Cottrell Boyce (Millions) and Simon Vaughan (War and Peace), Goodbye Christopher Robin was produced by Damian Jones (Absolutely Fabulous: The Movie, The Lady in the Van) and Steve Christian (Belle).
The biopic also stars Allison Janney, Bobby Cannavale and Caitlin Carver, and is set for release on 8 December.