It was Maslany's second nomination for the sci-fi series. In Season 4, she played eight characters (all clones). She has played a total of 11 characters over the course of the series.
"I feel so lucky to be on a show that puts women at the center," she said in her acceptance speech.
Maslany bested last year's winner Viola Davis for How to Get Away with Murder, as well as Taraji P. Henson for Empire, Keri Russell for The Americans, Robin Wright for House of Cards, and Claire Danes, who took her third straight loss after winning twice for Homeland in 2012 and 2013.