She has also been nominated for a Best Actress Oscar for her portrayal of the last Stuart monarch in the film with that award handed out in Hollywood on February 24th 2019.
Costume romp "The Favourite" was the biggest victor at the BAFTAs on Sunday, taking seven awards, but Netflix black and white film "Roma" picked up the Best Film prize, as well as Director, at Britain's top movie honors.
Looking visibly shaken as she walked up to the stage of London's Royal Albert Hall, the actress - who played Queen Anne in The Favourite - clutched a piece of paper with her notes on what to say.
"We're having an incredible night aren't we", Colman told her fellow "The Favourite" nominees as she picked up the award.
"If they do good movies, they should be recognised. We're going to get so (drunk) later", Colman told her fellow "The Favourite" nominees as she picked up the award to loud cheers.
"The thing I really want to do is, Emma and Rachel (must keep this together) not just for your performances but for what you did after the cameras stopped rolling".
"This isn't for the lead it's for 'a' lead and as far as I'm concerned all three of us are the same and should be the lead and it's weird that we can't do that".
Despite failing to win Best Picture, "The Favorite" was honored as best British film and claimed several other top awards at the BAFTA ceremony.
Colman thanked her co-stars Weisz and Emma Stone while accepting the award at London's Royal Albert Hall on Sunday evening, United Kingdom time. "It's got my name on it, but we can scatch some other names on".
Roma also won Best Cinematography, Best Foreign Language Film and Best Director for Alfonso Cuaron.
Rami Malek scooped the leading actor category for his turn as Freddie Mercury in Bohemian Rhapsody, while Mahershala Ali was named best supporting actor for Green Book, beating British favourite Richard E Grant in Can You Ever Forgive Me?
A Star is Born won the prize for best original music, accepted by the film's writer, director and star, Bradley Cooper.
In his acceptance speech, Malek thanked the late Queen's frontman as "the greatest outsider of them all". The Bafta Fellowship went to Thelma Schoonmaker, film editor to Martin Scorsese for more than 50 years. Best British short film was "73 Cows", while Vice won the best editing.