Though she was raised Jewish, she told the Jewish Journal of Greater Los Angeles, that Judaism "is an important part of my history, but, as a whole, religion is not a part of my life."
Kat Dennings was homeschooled and graduated early at the age of 14. She grew up near Bryn Mawr, "but I basically grew up in the woods. There were deer on my lawn. It was totally awesome. That's why I'm so socially weird" (phillymag.com).
Kat Dennings chose a stage name because "I didn't want to use my family name because I thought, A, it was a little hideous, and B, I wanted to know when someone really knew me or they didn't."
Kat and her family moved to Los Angeles so that she could act full time. Her first acting job was a commercial for potato chips. Other roles followed, including "Sex and the City," "Raising Dead," "The Scream Team," "Everwood," "Without a Trace," "Less than Perfect," "ER," and "CSI: NY."
Kat Dennings' film roles include "The 40-Year-Old Virgin," "Big Momma's House 2," "Charlie Bartlett," "The House Bunny," "Nick and Norah's Infinite Playlist," and "Thor."
Dennings has also kept a personal blog since 2002, though she said, "the blog is kind of winding down. I mean, I'll leave it up for the archives but for the most part, yeah, I mean I doubt I'll be doing that because I have a Twitter now" (collider.com).
Kat Dennings told BlackBook magazine that "I don't drink and I don't smoke and I don't like being around people who do." In an interview with GQ, she said, "I don't think I'm a weirdo in a bad way, there's just a lot going on in my head." She added, "I get obsessed. That could be it " how I get obsessed with things. Though I think if I could put my finger on my exact weirdness I'd be able to change it." She followed that she hates the description "quirky." "I hate that damn word! Quirky is what a guy would call a girl he doesn't understand."
Of Hollywood, Kat Dennings said, "Shit is crazy out here. I tried being anorexic for four hours, and then I was like, I need some bagels. I'll never feel comfortable in L.A., really. I knew these nice girls that lived in the Valley. I had no idea they were on meth."