Stone's role as an aspiring actress in romantic musical comedy-drama film "La La Land", was up against competition from Amy Adams ("Arrival"), Emily Blunt ("The Girl on the Train"), Meryl Streep ("Florence Foster Jenkins") and Natalie Portman ("Jackie").
For the ceremony at the Royal Albert Hall here, Stone chose to wear matching trousers under her Chanel dress which had a plunging neckline, guardian.com reported.
Meanwhile, Affleck — who plays a man who looks after his teenage nephew after the boy's father dies, in "Manchester By The Sea" — was competing with Andrew Garfield ("Hacksaw Ridge"), Jake Gyllenhaal ("Nocturnal Animals"), Ryan Gosling ("La La Land") and Viggo Mortensen ("Captain Fantastic").