Olympic wrestling champion Mark Schultz (Channing Tatum
) speaks at an elementary school in place of his brother, Dave Schultz (Mark Ruffalo
), who is also an Olympic gold medal-winning wrestler. Despite his achievements, Mark lives in relative squalor. He is contacted by philanthropist and wrestling enthusiast John E. du Pont (Steve Carell
), an heir to the E.I. du Pont family fortune, who arranges to fly Mark to his sprawling 800-acre estate,"Foxcatcher Farm", located in the western Philadelphia suburb of Newtown Square in Delaware County, Pennsylvania and shows Mark the lavish 14,000-square foot, $600,000 private wrestling training facility called the Foxcatcher National Training Center that du Pont had built on his property. Du Pont then invites Schultz to join his private wrestling team, "Team Foxcatcher", where he will coach, train for the World championship, and be paid handsomely. Mark accepts the offer with du Pont urging him to enlist his brother Dave as well. Dave declines for the sake of his wife and two kids who are settled where they live, however, so Mark moves to du Pont's estate alone.
Mark stays in a homey guest house ("the chalet") and is greeted there later in the night by du Pont, wanting to ensure his guest is comfortable. Through training with his new teammates and du Pont's financial support, Mark excels with Foxcatcher, winning Gold at the 1987 World Wrestling Championships. Du Pont gives him much praise and wants the world to see him as a great coach and mentor. Du Pont introduces Mark to cocaine. During this period, du Pont confides in Mark, whom he now calls a true friend, and tells him how his mother, Jean du Pont (Vanessa Redgrave
) paid a boy to act as his friend. Jean du Pont tells her son that she believes that the sport of wrestling is a "low sport" and doesn't like seeing him be low. One day, Mark and his teammates in Foxcatcher take a morning off from training to watch mixed martial arts (MMA) on TV. Angered by this (as well as Mark insisting that his brother will not join Team Foxcatcher), du Pont verbally and physically rebuffs him, saying that he'll enlist Dave by any means necessary.
Dave decides to move with his family to Pennsylvania so he can join Foxcatcher. His stable training environment threatened by du Pont, Mark decides to work and train alone, pushing du Pont and even Dave away. As Team Foxcatcher prepares to enter the preliminaries for the 1988 Summer Olympics in Seoul, du Pont's mother is escorted into du Pont's gym to watch him coach his team. He awkwardly demonstrates basic maneuvers for her and the other wrestlers. Jean leaves in disgust after seeing du Pont give his back to his student.
At the preliminaries, Mark performs poorly, losing his first match. Deeply angered by his failure, Mark violently destroys his room, sobs deeply, and goes on an eating binge. His brother Dave manages to break into his room and is alarmed at his brother's condition. Mark breaks a personal weight cutting record losing 12 lbs in 90 minutes to make weight; As Mark exercises, Dave prevents du Pont from speaking with Mark. Mark defeats 2-time NCAA Champion and NCAA "Outstanding Wrestler" Mike Sheets and makes the Olympic team. Dave notices that du Pont is absent, learning that he left for Pennsylvania after being told his mother had died. After returning to the estate, Mark tells Dave that "you and I both know that I can't stay" at Foxcatcher once the Olympics are over and asks Dave to leave with him as well. A documentary funded by du Pont about his exploits with Team Foxcatcher is made, during which Dave is asked to praise him as coach and mentor. Mark loses his matches in Seoul.
Mark leaves du Pont's estate, but Dave negotiates a deal with du Pont to continue to support him financially so he can pursue competition. Dave continues to live at du Pont's estate and train with Foxcatcher. Du Pont is bewildered by his devotion to his family and independence from his control.
Eight years later du Pont is sitting alone in his mansion's trophy room on January 26, 1996 watching the documentary made on Team Foxcatcher which ends with Mark giving a glowing compliment to du Pont at a ceremony depicted earlier. Du Pont then calls his bodyguard and drives to Dave Schultz's nearby home where he finds him in the driveway working on his car. As Schultz approaches du Pont's car John rolls down his window as asks him "Do you have a problem with me?" As a puzzled Dave replies "No" to the question, without another word du Pont summarily shoots him at close range three times with a .44 caliber handgun and drives off as Dave dies in his wife's (Sienna Miller
) arms after she had called 911. After a two day siege with the heavily armed du Pont holed up in his mansion surrounded by 75 police officers which includes a 30-man SWAT team, du Pont is seized and arrested by Newtown Township police, a department of which he had been an unpaid but full badge carrying member since the 1970's, and is charged with first degree murder by Delaware County's District Attorney (and now U.S. Congressman, R-PA7) Patrick Meehan and Delaware Country Prosecutor Joe McGettigan (who also put Jerry Sandusky behind bars). The film ends showing Mark as he later competes and wins a bare-knuckle "No-Holds-Barred" cage fighting match with the crowd's cheers ringing in his head.
Dave was posthumously inducted into the Wrestling Hall of Fame and was survived by his wife and two children. Mark never wrestled again after the 1988 Olympic games, switched sports to Brazilian Jiu-Jitsu and Submission Grappling, and ended his athletic career going out a winner in the Ultimate Fighting Championships IX in 1996. Mark now speaks professionally for Keppler Speakers on overcoming adversity and winning. His book "Foxcatcher: The True Story of My Brother's Murder, John du Pont's Madness, and the Quest for Olympic Gold" is a New York Times best-seller. After a three week trial and seven days of jury deliberation, on February 25, 1997 du Pont was found guilty but mentally ill of murder in the third-degree. According to prosecutor Meehan, du Pont was the richest American ever tried for murder. Du Pont was eventually transferred from Norristown State Hospital where he had undergone psychiatric treatment to Laurel Highlands State Prison in Somerset, PA, where he died of natural causes almost 14 years later on December 9, 2010 at age 72.