Born to Gujarati immigrants, Kal Penn was involved in acting during his student years. When he was in high school, he participated in school productions and was also active with the forensics team. He then attended UCLA, where he majored in sociology and film.
He made his film debut in 1998, and has since appeared in films such as American Desi and Van Wilder. His biggest break came in 2004, when alongside John Cho, he appeared in the stoner comedy Harold & Kumar Go To White Castle; its success spawned a sequel, which was released in 2008.
Penn's first regular television role came in 2007, when he joined the cast of 24 as teenage terrorist Ahmed Amar. He was initially reluctant to take the role. Later that year he joined the cast of the Fox series House, as fellowship applicant Lawrence Kutner. He stayed in the series in 2009, when he asked the producers to write his character off, as he accepted a job with then newly-elected President Barack Obama.
Penn's interest in politics go back to his childhood; he frequently cited his grandparents' involvement in Mahatma Gandhi's struggle for Indian independence. He was a frequent face during Obama's campaign for the presidency. In 2009, he joined the White House as Associate Director of the Office for Public Engagement. He briefly left the job to shoot a third Harold & Kumar film, but returned in November 2010.
- He is a fan of Bollywood actress, Kajol.
- Despite what his character did in Harold & Kumar Go to White Castle, Penn is a vegetarian, and believes marijuana is not for him.
- Express: Aisle to Glory (1998)
- Freshmen (1999)
- American Desi (2001)
- Hector (2002)
- Van Wilder (2002)
- Badger (2002)
- Where's the Party Yaar? (2003)
- Malibu's Most Wanted (2003)
- Love Don't Cost A Thing (2003)
- Arrangement (2004)
- Harold & Kumar Go To White Castle (2004)
- Awesometown (2005)
- Dancing in Twilight (2005)
- Son of the Mask (2005)
- A Lot Like Love (2005)
- Dream (2005)
- Man About Town (2006)
- Superman Returns (2006)
- The Namesake (2006)
- Van Wilder 2: The Rise of Taj (2006)
- Epic Movie (2007)
- Harold & Kumar Escape from Guantanamo Bay (2008)
- 24 (recurring, 2007)
- House (regular, 2007-2009)
“I just go nuts every time I am in a coffee shop and someone walks up and says, ‘Can I get a chai tea latte?’ Lady, do you know how redundant that is—chai and tea—and there’s already milk in the chai, so what’s a chai tea latte? You just know she is going to do yoga and watch a foreign film she rented.”