The 33-year-old actress wowed in a royal blue off-the-shoulder Preen dress at the event. And if the ensemble looked familiar, it’s because Kate Middleton sported a cherry red version of the dress in September 2016 while on her Royal Tour of Canada.
The regal look retails for around £999 (roughly $1,250), Moore paired the dress with silver heels while the Duchess of Cambridge, 35, matched her dress with red pumps.
ET spoke with Moore at the screening about her recent Billy on the Street appearance, in which she attracted the attention of a random stranger while out with her co-stars.
"I was so happy to finally get to be a part of [Billy on the Street] and I've never been asked out before by a stranger like that," Moore confessed to ET. "That was a whole new experience for me, so I told my boyfriend afterwards because I was really flattered."
For more on the hilarious encounter, watch the clip below!