Branagh accepted the award at London’s Royal Albert Hall, saying: "Thank you to British cinema audiences for watching in tonnage a UK and Irish cinema film at UK and Ireland cinemas.
"All hail the streaming revolution, but all hail the big screen too. It's alive, and long may they live together.
"This is a black and white film about the Troubles. It was not an easy pitch, but when the great talent in this room dreams up anything similarly unlikely to make or to finance, please remember if you build it, they will come.
"Build it with passion and truth and believe in the originality and uniqueness of your story and your voice and believe in the imagination of the public to embrace every and any kind of story well told.
"We are so proud to be included in this year's films; they are all outstanding. Thank you very much for being so kind to ours, we deeply appreciate it."
‘Belfast’ was also nominated for the Best Film award, but was ultimately beat out for the accolade by ‘The Power of the Dog’.
Branagh’s semi-autobiographical film was also unsuccessful in nabbing the Best Original Screenplay award, which went to Paul Thomas Anderson’s ‘Licorice Pizza’ instead.
