The Bafta awards took place in Britain on Sunday night.
The stars came out in there droves.
Funny-Irishman Graham Norton hosted the event.
Gleeson was nominated for his role as Winston Churchill.
However, the award was taken by another Irishman Kenneth Branagh for his role in the movie "Wallander."
Other winners on the night was HBO"s "Mad Men" who took the award for International gong, beating the likes of "Family Guy" and "True Blood."
Gleeson's movie, "Into the Storm" was released in the U.S. on HBO.
Gleeson starred alongside Tony award-winner Janet McTeer, who was cast as Churchill's wife.
"Into the Storm" is a continuation of "The Gathering Storm," an Emmy-winning HBO movie from 2002.
The new movie reflected on Churchill's leadership during wartime.
The Los Angeles Times described Gleeson as a powerful Churchill, "enthralling himself into the performance."
The movie shows Churchill's character hardened by years of war, making him difficult as a peacetime leader.
According to the Associated Press, Gleeson says, "Winston was a bit of a challenge, all right, from a lot of different perspectives."
Gleeson, 54, gained his confidence from intense work on the accent and diction necessary to portray Churchill.
The cast also included Len Cariou, as President Franklin D. Roosevelt; Ian Glen and James D'Arcy.