He is best known for his role as Alby Grant in the HBO series, Big Love and as Eddie Scott in the 2005 film Good Night, and Good Luck, for which he was nominated for a Screen Actors Guild Award for Outstanding Performance by a Cast in a Motion Picture. He also directed the feature film 28 Hotel Rooms. In 2011, he played Dr. Charles Montgomery on the first season of FX's anthology series American Horror Story.
- Matt Ross is one of the twenty-four cast members that portrayed the same character in different seasons. He portrayed Dr. Charles Montgomery in Murder House and Hotel.
- Murder House - Charles Montgomery
- Halloween: Part 1 - Charles Montgomery
- Piggy Piggy - Charles Montgomery
- Open House - Charles Montgomery
- Spooky Little Girl - Charles Montgomery
- Birth - Charles Montgomery
- Room 33 - Charles Montgomery