The couple graced the Vanity Fair EE Rising Star Party on Wednesday ahead of the Bafta awards later this month. Just days earlier, Ed had revealed the romantic proposal during a picturesque Swiss vacation.
The actress, looked stunning in a black velvet gown as she proudly posed alongside her soon-to-be husband, though she chose to keep her diamond engagement ring under wraps, concealed beneath a pair of coordinating gloves.
Westwick, 36, who played Chuck Bass in the US teen drama Gossip Girl, which ran from 2007 until 2012, popped the question during a ski trip in Switzerland.
Taking to Instagram on Monday, he and Jackson, 31, shared a joined post revealing their happy news, along with a slew of images of the big moment.
The accompanying caption read: "Hell YES!"
This will be the first trip down the aisle for both of them.
Jackson, who has starred in a string of Indian films, predominantly in Tamil, Hindi, and Telugu languages, was previously engaged to hotelier George Panayiotou, with whom she shares four-year-old son Andreas.
Westwick and Jackson first met at Silverstone racetrack in 2021 where both were attending an Aston Martin event.
He then asked her out on a coffee date with their dogs, her poodle Herbert and his Frenchie, Humphrey. They went Instagram official in June 2022 and have since featured regularly on each other's social media accounts.
The couple weren't the only famous faces in attendance at the pre-Bafta event on Wednesday night.
Rising Star nominees Sophie Wilde and Mia McKenna-Bruce stepped out for the soiree alongside One Day actors Leo Woodall and Ambika Mod.
BBC Radio 2 presenter Vernon Kay made a family night of it as his daughter, Phoebe, joined him for the glitzy event held at the Four Seasons Hotel Park Lane.
At the event, attendees feasted on light bites by Pavyllon London and Bar Antoine while sipping on drinks by created in partnership with Don Julio Tequila.
The event was in celebration of the only category at the EE BAFTA Film Awards voted for by the public, ahead of the ceremony itself on February 18.