Penn & Teller Tell a Lie is a six-part series starring Penn Jillette and Teller. Each episode contains six or seven stories, including a demonstration performed by the hosts during the recording of the show as the last story. One of the stories is falsified, and the rest are true. During each broadcast, viewers can guess which story is the lie, voting on Discovery's website, with the answer and voting results revealed at the end of the episode.

The series aired on the Discovery Channel beginning Wednesday, October 5, 2011.

The show is also broadcast in the UK on Channel Quest which premiered on 2 May 2012.