The A Very Harold and Kumar Christmas actor revealed that his role in the stoner comedy never came up when interviewing for a position in President Barack Obama's administration, the New York Times reports.
"You have to list the jobs you've been fired from, and the two jobs I was fired from were sitcom pilots, because the executive producer didn't believe I was funny enough," Penn recalled.
He continued: "So I was looking at these forms like, 'How do I word this in a diplomatic way, because I want to be honest?' And I wrote, 'Fired for not being funny enough'."
Penn recently insisted that Hollywood and Washington DC are very different, describing his time in DC as a "culture shock".
The actor has said he is happy to be making films again after working as a White House staffer for a year.
A Very Harold & Kumar Christmas is currently on US release, and reaches the UK on December 9.
Watch the trailer for A Very Harold & Kumar Christmas below: