Production notes

Scout Productions acquired the life rights of boxer Micky Ward and his brother, Dick Eklund, in July 2003. Eric Johnson and Paul Tamasy were also hired to write the screenplay, which was rewritten by Lewis Colick. In an interview with producer Todd Lieberman, he revealed that rapper Eminem fresh off the success of 8 Mile (2002) was originally the first choice for the role of Micky Ward, however Eminem turned the offer down. Matt Damon was also considered for the role of Micky Ward. Mark Wahlberg joined the production in early 2005, with the intention of doing Ward's life story "justice. We don't want to do any over-the-top, unrealistic fight scenes." The Fighter had been a longtime passion project for Wahlberg, who was a fan of Ward's since his youth growing up in Boston. Paramount Pictures, the United States distributor of the film, hired Paul Attanasio to rewrite Collick's draft in February 2007 in an attempt to emphasize the themes of brotherhood and redemption. Hoping to start production in Massachusetts in June 2007, Wahlberg had Martin Scorsese read the screenplay, hoping he would direct. Scorsese turned down the offer, finding the Massachusetts-setting redundant after having finished The Departed (2006). The actor cited Scorsese's Raging Bull (1980) as an influence for The Fighter, but Scorsese was not interested in directing another boxing film. Darren Aronofsky was hired to direct in March 2007, with Scott Silver rewriting the script in September 2007. Attanasio was brought back in as a script doctor film prior to shooting.

"I’ve seen every boxing movie ever made. I’m also a huge fight fan. I fought a little bit when I was younger. Nobody in my opinion, and some of the greatest movies ever made – you talk Raging Bull and Rocky I saw 30 times – but the fighting just wasn't as realistic as what we hope to achieve and accomplish in this movie." Damon signed on to play Dick Eklund, but he later dropped out due to commitments to other projects and was replaced with Brad Pitt. Production proceeded with filming set to begin October 2008 and Christian Bale replaced Brad Pitt. By then Aronofsky had dropped out to work on MGM's RoboCop (2014), followed by Black Swan (2010). After Pitt and Aronofsky dropped out, Wahlberg signed on as a producer to switch the film as a big budget studio picture to an indie film. At one point, Catherine Hardwicke expressed interest in directing, but was told by producers the film had to be directed by a man. Wahlberg and Bale chose David O. Russell as Aronofsky's replacement. Wahlberg had also starred in Russell's Three Kings (1999) and I Heart Huckabees (2004). Aronofsky was given an executive producer credit for his contributions on The Fighter, and was enthusiastic to have Russell as the director. In April 2009, Relativity Media stepped up to entirely finance the film, selling the international distribution rights to the Weinstein Company (TWC) a month later. The Fighter began principal photography on July 13, 2009, in a 33-day shooting schedule. The budget was reportedly $11 million, although Brad Grey from Paramount disputed that figure and other sources put the budget at $25 million. The production used Massachusetts' film tax credits to cover parts of the film's cost.

Principal photography took place on location in Ward's hometown of Lowell, Massachusetts. Its boxing matches were shot at the Tsongas Center at UMass Lowell, and gym scenes at Arthur Ramalho's West End Gym, one of the real-life facilities where Ward had trained. The boxing-match footage was created "in big, choreographed sections that were taken directly from [video of] Micky's actual fights", said Russell. "And we used the actual commentary from [HBO's] Larry Merchant, Roy Jones Jr., and Jim Lampley." Russell used "[t]he actual cameras from that era. [They were] a sort of Beta [video-format] camera that gave a very certain look, and we actually hired the director from HBO and his crew who had done those fights" to replicate them shot-for-shot.

The film has Ward on a losing streak coming into the 1988 Mike Mungin fight. In reality, Ward was 18–1 and on a four-fight winning streak when he fought Mungin. Ward's four-fight losing streak actually took place in 1990–91. In the film, Ward is knocked down in round six of the Neary fight. In reality, Ward was not knocked down in that fight. The film has Ward's career record as 30–7, with 20 KOs, as he fights Neary. In reality, his record at that time was 34–9 with 25 KOs. The film depicts Ward taking a severe beating in the Mungin fight. In reality, the fight went the full ten rounds and Mungin won by very narrow decision: 96–93, 95–94, 95–94. In the film, during Ward's fight with Alfonso Sanchez, which took place on April 4, 1997, Ward's entrance song is "The Warrior's Code" by Dropkick Murphys. However, that song was not released until 2005 on their album of the same name.

The Fighter grossed $93.6 million in United States and Canada and in other territories it collected $35.5 million, for a worldwide total of $129 million; the film made a profit over its $25 million budget.

Review aggregation website Rotten Tomatoes gives The Fighter a rating of 91% based on reviews from 256 critics, with an average rating of 7.8/10. The site's critical consensus reads: "Led by a trio of captivating performances from Mark Wahlberg, Christian Bale, and Amy Adams, The Fighter is a solidly entertaining, albeit predictable, entry in the boxing drama genre." Metacritic gives the film an average score of 79 out of 100, based on 41 critics, indicating "generally favorable reviews". Audiences polled by CinemaScore gave the film an A− grade.

Sports Illustrated dubbed the film the best sports film of the decade, and "one of the best since Martin Scorsese backlit Robert De Niro's Jake LaMotta in Raging Bull". Richard Corliss of Time magazine named Christian Bale's performance one of the Top 10 Movie Performances of 2010, saying "In a little festival of tart, savory performances, notably from Melissa Leo as the boys' mother and Amy Adams as Micky's girlfriend, Bale shines the brightest, because he knows that no character, however depraved his status, is only a monster. He finds beauty in the beast". Several critics commented that underdeveloped characters, particularly those of Micky and Alice, was the main weakness of the film. Roger Ebert praised the performances of Wahlberg, Bale, Leo, and Adams, but concluded, "Because we aren't deeply invested in Micky, we don't care as much as we should, and the film ends on a note that should be triumph but feels more like simple conclusion." The Hollywood Reporter's Kirk Honeycutt expressed, "The most luminous personality in the film belongs to Adams' Charlene. She too is a woman who takes charge but she does it through strength of character and love. Her bad-girl days are behind her so she understands a thing or two about comebacks: They only work if you see no other option." Peter Debruge of Variety wrote, "If 'The Fighter' feels like kind of a mess, lurching from one scene to the next as if the film itself has taken a few hits to the head, that's not entirely a bad thing. Since the story ends well before Micky's career-defining showdown with Arturo Gatti, it's just as well that lunatic setpieces allow talents such as Leo — whose wickedly over-the-top turn disguises Alice's cartoonish two-dimensionality — to upstage anything Micky accomplishes in the ring." Though Debruge opined the film is an entertaining one, he said "what’s missing are stakes and soul, with the director's attention split between working-class elegy and white-trash caricature, but missing the big picture." In a mixed review, Eric Kohn of IndieWire commented the film plays "as if Russell and screenwriters Scott Silver, Paul Tamasy and Eric Johnson couldn’t decide if they wanted to go the 'Rocky' route and emphasize the sport's brutal nature or play up the family's larger relationship issues".

The film received seven Academy Award nominations, winning two with Best Supporting Actor for Bale and Best Supporting Actress for Leo, marking the first film to win both awards since Hannah and Her Sisters in 1986. The film was nominated for six Golden Globe Awards: Best Picture (Drama), Best Actor (Drama) for Wahlberg, Best Supporting Actress for Leo and Adams, Best Supporting Actor for Bale, and a nomination for Best Director for Russell. The film received three Chicago Film Critics award nominations: Best Supporting Actor for Bale, and Best Supporting Actress nominations for Adams and Leo. Bale won a Satellite Award, the Critics' Choice Award, the Golden Globe for Best Supporting Actor, and the National Board of Review Award for Best Supporting Actor. Leo won the Golden Globe for Best Supporting Actress.