After that, she appeared in films like "10 Things I Hate About You," starring Heath Ledger, "American Beauty," with Kevin Spacey, and "Nurse Betty" starring Renee Zellweger.
She also tried her hand at Broadway and earned a Tony nomination for her portrayal as Janice in the Broadway revival of Arthur Miller's "A View From the Bridge"
Janney became part of the original cast of "The West Wing" in 1999, playing press secretary (and later chief of staff) "C.J." Cregg. She would receive four Emmys for that role.