In 2016, she starred in Teenage Mutant Ninja Turtles: Out of the Shadows.Linney starred as Mary Ann Singleton in the television adaptations of Armistead Maupin's Tales of the City books (1993, 1998, and 2001).Having taught Harp, Cello and Recorder (with 100% ABRSM pass rate) for the past eight years, Stephanie has become adept at educating pupils of all abilities and ages.Alongside her teaching, Stephanie has performed for a wide variety of weddings, parties and special events, including The Great Hall in Winchester, Christchurch Priory and Lymington Sea Wall. From 2010–13, she starred in the Showtime series The Big C, which won her a fourth Emmy in 2013.In 2017, she began starring as Wendy Byrde in the Netflix crime drama series Ozark. She made her screen debut in the film Lorenzo's Oil (1992) and went on to receive Academy Award nominations for You Can Count On Me (2000), Kinsey (2004), and The Savages (2007).
She has a half-sister named Susan from her father's second marriage.
The latter film earned her a BAFTA Award nomination for Best Supporting Actress.
Her 2004 performance in Kinsey, again as the title character's wife, was nominated for the Academy Award for Best Supporting Actress.
In 2007, Linney appeared in the spy thriller Breach, the comedy-drama The Nanny Diaries opposite Scarlett Johansson and Chris Evans, and based on the book by Emma Mc Laughlin and Nicola Kraus, In 2008, Linney starred in The Other Man, opposite Liam Neeson, with whom she had starred in Kinsey and Love Actually, and Antonio Banderas.
In 2012, she starred opposite Bill Murray in Hyde Park on Hudson.