She accepted the award using her American accent which tickled Twitter.
Anderson was born in the US, and grew up in Puerto Rico and London before returning to the States.
While the American series “The X Files” made her a star, she has had plenty of roles in British productions including Netflix’s dramedy “Sex Education,” BBC’s “Bleak House” adaptation and the crime drama “The Fall” which was set in Northern Ireland.
Anderson has lived in London now for years.
“Part of me wishes I could control it, but I can’t,” she said. “I just slip into one or the other. When I moved to the States I tried hard to cling on to my British accent because it made me different.’
Correction: An earlier version of this story misstated the location of “The Fall.” It is set in Northern Ireland.