"Kids" is about a lesbian couple whose happy home life is turned upside-down when their teenage children try to get to know their biological father.
"It was a labor of love for all of us. To be able to unite that with a moment like this is truly phenomenal," Bening said as she collected her trophy.
Paul Giamatti won the Globe for Best Actor in a Comedy Film for his work in "Barney's Version."
"I'm a little jacked up because I ate five boxes of the free Godiva chocolates," he joked.
"I always think that a mistake has been made because the other gentlemen in this category are my superiors in every regard as men and actors, so I acknowledge them," he said, referring to fellow nominees Johnny Depp, Jake Gyllenhaal and Kevin Spacey. "('Barney's Version') is an extraordinary movie to be a part of and people busted their asses to get it made."