"Downton" is an international sensation, being the most-watched series on PBS in the U.S. and ITV in the U.K. It also received nominations for Michelle Dockery, who plays Lady Mary Crawley, and Maggie Smith, who plays the Dowager Countess of Grantham, both in the category of female actor in a drama series.
It's the first SAG Award for the series, which is currently airing its third season on PBS. The third season aired last year in the UK.
It follows the travails of the aristocratic Crawley family and the servants in their home, Downton Abbey. The series' fourth season is set to begin production next month.