Justin Lee Bartha is an American actor. In film, Bartha has played Riley Poole in the National Treasure film series and Doug Billings in The Hangover trilogy. His television roles include David Sawyer in the NBC comedy series The New Normal as well as Colin Morrello in the CBS All Access legal and political drama The Good Fight.

The Hangover is a series of American comedy films created by Jon Lucas and Scott Moore, and directed by Todd Phillips. All three films follow the misadventures of a quartet of friends who go on their road trip to attend a bachelor party. While all of the films find three of the four men on a mission to find their missing friend, the first two films focus on the events after the nights of debauchery before a party, respectively in Las Vegas and Bangkok, whereas the third and final film involves a road trip and a kidnapping in lieu of a bachelor party. Each film in the series focuses on how the friends deal with the aftermath of their antics, while they are being humiliated and occasionally physically beaten up at every turn. All three films were released from 2009 to 2013, and have grossed a collective total of $1.4 billion in the United States and worldwide.