Dame Maggie was the first Brit of the night to win, earning her award for best supporting actress in a TV mini-series for her role as Violet Crawley in ITV's Downton Abbey.
But the veteran actress, who did not attend the ceremony in Los Angeles, missed out on a second gong for best actress in a comedy or musical in her latest film Quartet.
Singer Adele gushed "oh my God" repeatedly as she took to the stage with co-writer Paul Epworth to collect her award for best original song for a motion picture for their theme tune to the James Bond hit Skyfall.
The singer – who attended the ceremony with Robbie Williams's wife Ayda Field – was making her first appearance since giving birth.
Adele has kept a low profile since she gave birth in October.
She and boyfriend Simon Konecki have still to reveal the name of their son, although she took the opportunity to dedicate the award to him.