She received a Golden Globe Award for Best Supporting Actress – Motion Picture nomination for her role in American Splendor (2003).

She earned acclaim for her role in Yasmina Reza's God of Carnage in 2009 acting alongside Jeff Daniels, Marcia Gay Harden, and James Gandolfini.

Hope's early television roles include the Dick Wolf NBC series Deadline (2000–2001) and the ABC drama Six Degrees (2006–2007).

She later earned Primetime Emmy Award nominations for her performances in the HBO projects In Treatment (2009), The Special Relationship (2010), and Succession (2021–2023).

Davis made her debut as a dramatic actress in the Joel Schumacher directed psychological horror film Flatliners (1990), starring as William Baldwin's fiancée.

[5] Her major stage debut came after she starred in the Wisdom Bridge/Remains Theater co-production of David Mamet's play Speed-the-Plow for Joel Schumacher with William Petersen in Chicago in 1992.

In 1995 she had her first starring role as Eliza Malone D'Amico in the Greg Mottola directed independent comedy-drama The Daytrippers acting opposite Liev Schreiber, Parker Posey, Anne Meara and Stanley Tucci.

[13][14][15] Later, she had lead roles in the New York premiere of Rebecca Gilman's Spinning into Butter in 2000, and in the 2005 audio play Hope Leaves the Theater, written and directed by Charlie Kaufman.

[16] In 2005 she took supporting roles in the black comedy The Matador, the John Madden directed drama Proof, and the Gore Verbinski comedy-drama The Weather Man.

She portrayed socialite Slim Keith in the Truman Capote biopic Infamous starring Toby Jones.

Mia is a successful, unmarried malpractice attorney who returns to therapy with Dr. Paul Weston after a 20-year absence because of a lack of stability in her personal life.

Also in 2009 Davis returned to Broadway starring in Yasmina Reza's play God of Carnage with Marcia Gay Harden, James Gandolfini and Jeff Daniels.

[25] Davis also starred in the short-lived NBC television drama, Allegiance (2015), where she plays Katya O'Connor, an ex-KGB agent.