She also appeared in the films Rounders (1998), Celebrity (1998), The Thirteenth Floor (1999), The Notorious Bettie Page (2005) – in which she played the title character – 3:10 to Yuma (2007), and Manchester by the Sea (2016).

[3][4] Mol's acting career began in summer stock theatre in Vermont where she played a variety of roles, including Godspell and 110 in the Shade.

[3] She played Jenny in Neil LaBute's The Shape of Things on stage in both London and New York in 2001,[5] in a role she reprised in the film version, released in 2003.

The New York Times critic Ben Brantley, in his review of the play (which he disliked),[6] wrote, "[Mol] gives by far the most persuasive performance as the unworldly Jenny, and you wind up feeling for her disproportionately, only because she seems to be entirely there, in the present tense".

[8] In 1998, she appeared in several notable films, including Rounders, starring Matt Damon and Woody Allen's Celebrity opposite Leonardo DiCaprio.

For her second film with Woody Allen, 1999's Sweet and Lowdown, she played a minor role which the Greenwich Village Gazette called "notable".

Mol had a small role of Maggie Tilton in the 1996 miniseries Dead Man's Walk, based on the Larry McMurtry novel.

[8] She was among the three lead actresses in David E. Kelley's 2002 series girls club, though it ended after its second episode due to underwhelming ratings.

She appeared in two TV remakes of classic films: Picnic (2000), in the role of Madge Owens, and The Magnificent Ambersons as Lucy Morgan (2002).

She made a Hallmark Hall of Fame television movie in January 2007, starring in The Valley of Light, a story set in post–World War II based on a novel by Terry Kay.

[16] She played NYPD Officer Annie Norris in the ABC series Life on Mars, the U.S. remake of the British show of the same name.

"[22] Mol serves as the national spokesperson in the United States for the PMD Foundation, which funds research and awareness of Pelizaeus–Merzbacher disease, a neurological disorder which affects children worldwide.