Beginning in 2017, Morton has starred in the Hulu period drama series "Harlots". She portrays Margaret Wells, the madam of a low-class brothel who seeks to improve her fortunes. The response from critics and audiences has been highly positive. "The Telegraph" found her to be the "standout performer", and "The Atlantic" noted: "While the role doesn't give Morton the same room to flex her acting muscles as, say, Woody Allen's "Sweet and Lowdown", she gives depth and moral conflict to a character who could easily be a pantomime dame in the wrong hands".