She was cast for a five-episode run on The WB's Everwood, but the role was recast with Nora Zehetner.
Dennings continued working on television, guest-starring on Without a Trace as a teen whose boyfriend goes missing, and on Less than Perfect in 2003.
Dennings starred in Charlie Bartlett in 2008, the story of a wealthy teenager (Anton Yelchin) who acts as a psychiatrist for his new public high school.
She played Susan Gardner, Bartlett's love interest, and the daughter of the school's principal (Robert Downey, Jr.).
and sometimes we would [tweet back and forth],” she said at the time. “Humor is such a huge thing for me, so, you know, the fact that we could talk about Monty Python and all sorts of weird other things, I was like, ‘OK, yeah, we’re on the same page.’” Dennings and Groban last stepped out together at Clive Davis’ pre-Grammys gala in Beverly Hills in February.
He was here in New York and we had a lovely week together where we hung out,' Dennings told her former co-star in Nick & Norah's Infinite Playlist.'We went and saw some plays.
From 2011 to 2017, she starred alongside Beth Behrs in the CBS sitcom 2 Broke Girls.
After making her acting debut in an episode of the HBO dramedy series Sex and the City, Dennings has since appeared in films including The 40-Year-Old Virgin (2005), Big Momma's House 2 (2006), Charlie Bartlett (2007), The House Bunny (2008), Nick and Norah's Infinite Playlist (2008), Defendor (2009), Thor (2011) and Thor: The Dark World (2013).
Following their impromptu photo shoot and with the sun well and truly sunk into the horizon, the pair stood up and shared one last romantic moment with Kat standing behind and hugging her much taller beau.
They stayed together as they mingled among the star-studded crowd including Caitlyn Jenner, Christina Aguilera, Chris Rock, Chrissy Teigen and John Legend, Sylvester Stallone, Avril Lavigne, Ellie Goulding and many more.
She also starred in the teen romance Nick and Norah's Infinite Playlist, with Michael Cera.
Dennings played Norah Silverberg, the daughter of a famous record producer, and was nominated for the International Press Academy's Satellite Award for Best Actress for the performance.
Then, on CSI: NY as Sarah Endecott, in the 2005 episode "Manhattan Manhunt".