Click on the photo to see all of Emma's premiere outfits...
was a vision in white as she stepped out for the London premiere of Noah.
The former Harry Potter
star was stunning in a backless Ralph Lauren Collection halter neck dress boasting a thigh-high split.
The ivory creation showed off her slim physique to perfection. Emma accessorised with matching Jimmy Choo clutch bag and heels and two silver wrist cuffs.
She kept her make-up minimal and styled her hair in a sleek chignon.
British-born Emma was clearly excited about being back in her home town for the premiere. "Final Noah premiere tonight in London's Leicester Square. #i'mhome," she posted on Twitter.
Emma has been giving a masterclass in the art of red carpet dressing during her promotional tour for Noah.
The 23-year-old has wowed in a series of stunning outfits including tuxedos and a black satin Oscar de la Renta ball gown.
Speaking about her role in the new movie on the red carpet, Emma said, "I loved my role.
"She's got such a huge heart. She's very wise, very relatable, and then you hear about the cast, it's like Russell Crowe and Sir Anthony Hopkins and Jennifer Connelly and Ray Winstone. And you realise that it's the opportunity to work with people who really are at the top of their game."
Emma also addressed rumours that have been swirling that she is to take on the role of Ariel in Sofia Coppola's live-action adaptation of The Little Mermaid.
"I'd be really intrigued to read a script," she told The Telegraph.
"I actually dressed up as Ariel for my fifth birthday. I mean I'd have to read it first. I love Sofia so much."