The blonde bombshell sauntered along in a sophisticated floor-length dress, which was covered in a white floral print.
The navy frock featured ruching across the stomach and a cut-out detail, which added a modern twist to the ladylike design.
Gorgeous Naomi, 45, oozed Hollywood glamour by parting her hair on the side and styling in loose curls.
She opted for classic make-up, slicking on a bold red lip while flaunting fluttery lashes and rosy cheeks. A sleek satin clutch and sparkling diamonds completed her polished look.
Naomi plays Diana, Princess of Wales in the biopic, which explores the last two years of her life and her relationship with heart surgeon Dr. Hasnat Khan.
The flick has already been released in the UK but hits US cinemas tomorrow (1 November).
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