The Conspirator is a 2010 American mystery historical drama film directed by Robert Redford and based on an original screenplay by James D. Solomon. It is the debut film of the American Film Company. The film tells the story of Mary Surratt, the only female conspirator charged in the Abraham Lincoln assassination and the first woman to be executed by the US federal government. It stars Robin Wright as Mary Surratt, together with James McAvoy, Justin Long, Evan Rachel Wood, Jonathan Groff, Tom Wilkinson, Alexis Bledel, Kevin Kline, John Cullum, Toby Kebbell, and James Badge Dale.

The Conspirator premiered at the Toronto International Film Festival on September 11, 2010 followed by a special premiere screening on March 29, 2011 at the Abraham Lincoln Presidential Library and Museum in Springfield, Illinois. Another premiere screening was held on April 10, 2011 at Ford's Theatre in Washington, DC, the site of the assassination. The US theatrical release took place on April 15, 2011, the 146th anniversary of the death of Lincoln. The film was released in Canada on April 29, 2011 and was in the UK on July 1, 2011. Lionsgate Home Entertainment released the DVD and Blu-ray on August 16, 2011.