Patriots Day is a 2016 American action thriller film based on the Boston Marathon bombings in 2013 and the subsequent terrorist manhunt. Directed by Peter Berg and written by Berg, Matt Cook, and Joshua Zetumer, the film is based on the book Boston Strong by Casey Sherman and Dave Wedge. It stars Mark Wahlberg, Kevin Bacon, John Goodman, J. K. Simmons, and Michelle Monaghan. It marks the third collaboration between Berg and Wahlberg, following Lone Survivor and Deepwater Horizon.

Principal photography began on March 29, 2016, in New York City, and also filmed in Boston, Los Angeles, New Orleans, and Philadelphia. The film premiered on November 17, 2016, at the AFI Fest. Distributed by CBS Films via Lionsgate, It was released in Boston, New York and Los Angeles on December 21, 2016, followed by a nationwide expansion on January 13, 2017. It received positive reviews for Berg's direction and the performances of its cast, and was chosen by the National Board of Review as one of the top ten films of 2016.The title refers to Patriots' Day, the Massachusetts state holiday on which the Boston Marathon is held.