Production notes

The film is set during a time when Irish migration to New York was thriving. The initial boom of Irish immigration to the US had started during the period following the Great Famine (1845–49). By the end of the Second World War, the rate of Irish migration to New York had declined, but new migrants were still able to find bustling Irish communities in which women were arguably a more significant presence than men. These women migrants were often active in the workplace, postponing marriage to find practical occupations in places such as supermarkets, eateries, and stores. Eilis makes her journey from Ireland to America in the 1950s, along with approximately 50,000 other migrants (around a quarter of whom moved to New York) as a part of the second minor wave of migration. Many of these migrants were in search of steadier jobs and a happier life. There were also smaller surges of migrants from many other countries at this time, expanding the trend of modern America becoming a vast land of different cultures.

Brooklyn is adapted from Irish writer Colm Tóibín's 2009 novel of the same name. The novel has been much-celebrated in the literary world, with The Observer naming it as one of "The 10 best historical novels" in 2012. In addition to this, it won the 2009 Costa Novel Award, was shortlisted for the 2011 International Dublin Literary Award, and was longlisted for the 2009 Booker Prize. The film is generally regarded as a faithful adaptation of the novel, with Tóibín noting the overall "authenticity" of the film in an interview with The Washington Post. The two works differ notably in how they end: in the novel, Eilis leaves Ireland, but her destination and ultimately her fate is left for the reader to decide, while the film ends with Eilis having a poignant reunion with Tony in Brooklyn. In Tóibín's later novel, Nora Webster, set in the 1960s, the author offers a glimpse of Eilis's later life during a conversation between that story's main character and Eilis's mother. The book and film have been praised for their refreshing perspective on the plight of the Irish migrant.

Principal photography began on 1 April 2014 in Ireland. The three weeks of filming in the country took place at locations in Enniscorthy, Wexford, and Dublin. On the first day of shooting, Ronan was spotted in period costume on the set in Enniscorthy. Production then moved to Montreal, Quebec, for four more weeks of filming. Two days were spent shooting in Brooklyn, one day of which was spent at the beach in Coney Island.

On the review aggregator website Rotten Tomatoes, 97% of 279 critics' reviews are positive, with an average rating of 8.5/10. The website's consensus reads: "Brooklyn buttresses outstanding performances from Saoirse Ronan and Emory Cohen with a rich period drama that tugs at the heartstrings as deftly as it satisfies the mind." Metacritic, which uses a weighted average, assigned the film a score of 88 out of 100, based on 45 critics, indicating "universal acclaim". Audiences polled by PostTrak gave the film an overall positive score of 92%, and over 80% of respondents said they would "definitely recommend" it. Brooklyn received a standing ovation following its premiere at the 2015 Sundance Film Festival. The British Film Institute called the film one of the best releases of 2015. In his review for the organization, Philip Kemp, describing ambiance and tone of the film, stated: "In some ways Brooklyn feels like a movie that's not just about, but also from, a more innocent age." He also pointed out that, while most immigrant stories are "male-led", Brooklyn is "female-led and all the stronger for it", concluding that "In this, as in most other ways, it's faithful to its source material." Donald Clarke of The Irish Times gave the film 4 out of 5 stars, noting that "Brooklyn is a most unconventional conventional romance." Clarke also wrote, "The film ultimately encounters the sort of near-accidental knot of deception that powered restoration comedies." Peter Bradshaw of The Guardian gave the film 4 out of 5 stars, calling it "a very heartfelt and absorbing film." Bradshaw highlighted Ronan's lead performance, stating that she "is the heart and point of this film" and "gives such a tremendous performance." A. O. Scott of The New York Times described the film as "an old photograph without a frame, an implied flashback" and wrote, "Brooklyn endows its characters with desires and aspirations, but not with foresight, and it examines the past with open-minded curiosity rather than with sentimentality or easy judgment." Scott also praised Ronan's performance, commenting that she "uses everything — her posture, her eyebrows, her breath, her teeth, her pores — to convey a process of change that is both seismic and subtle." In 2024, Looper ranked it number 45 on its list of the "50 Best PG-13 Movies of All Time," writing "The charming performances and amiable aesthetic of the entire production, all overseen by director John Crowley, make this the kind of low-key treat that's, much like most other movies Ronan's appeared in, impossible to resist."

Brooklyn grossed $38.3 million in North America and $23.7 million in other territories, for a worldwide total of $62.1 million, against a budget of $11 million. The Hollywood Reporter calculated that the film made a net profit of $3–4 million. The film's gross in Canada exceeded C$4 million, giving it the highest cumulative domestic gross of any Canadian film released in 2015. In Ireland, it earned over $650,000 from 87 cinemas its opening weekend, which was the biggest opening of any Irish drama in Ireland since Michael Collins opened to $662,000 in November 1996.

The film won the Audience Favorite Gold Award in World Cinema at the Mill Valley Film Festival, the Rogers People's Choice Award at the Vancouver International Film Festival, and the Audience Award for Best Narrative Feature at the Virginia Film Festival. Emory Cohen was named Breakthrough Performer at the Hamptons International Film Festival. Brooklyn received many nominations for industry and critics awards, including three nominations at the 88th Academy Awards: Best Picture, Best Adapted Screenplay, and Best Actress. Saoirse Ronan's performance was particularly praised, and, in addition to her Oscar nod, she garnered BAFTA, Critics' Choice, Golden Globe, and SAG nominations for Best Actress. She also won the BIFA for Best Performance by an Actress in a British Independent Film. Julie Walters was nominated for Best Supporting Actress at the BAFTAs. The film won the Canadian Screen Awards for Best Cinematography and Best Musical Score and the Quebec Cinema Awards (formerly known as the Prix Jutra) for Best Cinematography and Best Art Direction. The film was also featured on more than 120 film critics' "Top 10" lists of the best films of 2015, and was ranked 48th on the BBC's 2016 list of the 100 Greatest Films of the 21st Century. It is ranked as the fourth-best reviewed film of 2015 on Rotten Tomatoes and as fifth-best on Metacritic.