Tom Sherbourne, a traumatised and withdrawn hero of World War I, is hired as a lightkeeper at Janus Rock, a lighthouse off the coast of Western Australia. He falls in love with a local girl, Isabel Graysmark, and they marry in 1921. Isabel loses two pregnancies in three years, and fears she may never become a mother.
Shortly after Isabel's second miscarriage, a rowboat containing a dead man and a newborn baby girl washes up on the shore near the lighthouse. Tom knows that regulations require him to report the discovery. However, Isabel fears that the baby will almost certainly be sent to an orphanage, and persuades Tom to pass the baby off as their own. Tom grudgingly agrees. He buries the man on the island and they name the girl Lucy.
As Tom and Isabel are about to have Lucy christened on the mainland, Tom sees a woman, Hannah Roennfeldt, kneeling in front of a grave, bearing the names of Frank Roennfeldt and his baby daughter Grace Ellen, who were lost at sea on the day they found Lucy, 26 April 1923. Tom fears that Lucy might very well be Hannah's missing daughter. He writes anonymously to her to tell her that her husband is dead but that her baby is safe and well cared-for.
Four years later, Tom, Isabel, and Lucy, who have enjoyed an idyllic life together, attend a ceremony for the anniversary of Tom's lighthouse, and they strike up a conversation with Hannah and her sister, Gwen Potts. They learn that Frank was a German native, and had been accosted in the street by a drunken crowd. He jumped into a rowboat and fled along with his baby daughter. Tormented by his conscience, Tom sends Hannah a small rattle that was found with Lucy on the boat. One of Tom's co-workers recognizes the rattle on a reward poster, and reports him to the police.
Tom takes full responsibility, claiming he bullied Isabel into complying. Isabel is enraged that Tom is willing to give Lucy away, and breaks off contact with him after his arrest. Lucy is returned to her birth family, but initially rejects and hates them, having no memory of them. She refuses to answer to "Grace", and even runs away in an effort to go back to the lighthouse.
The police accuse Tom of murdering Frank, and are unable to draw an answer from the distraught Isabel as to whether he was dead when they discovered him. Just as Tom is about to be taken to Albany for trial, Isabel reads a letter which Tom had sent her, writing of how he had not deserved his happiness with her and how carrying the blame will assuage his guilt for surviving the war. She jumps on the boat and confesses everything. Moved by their gesture, Hannah offers to speak on their behalf at trial. Lucy has at last begun to bond with her natural mother and grandfather, who agrees to call her "Lucy-Grace" as a compromise.
In 1950, an adult Lucy-Grace Rutherford, accompanied by her baby son Christopher, tracks Tom down. She has not been in contact with the Sherbournes for over twenty years, as they had agreed not to contact her for the rest of her childhood. Isabel has recently died, still tormented with guilt for her actions, and Tom gives Lucy-Grace a letter that she wrote for her in case she ever made contact. An emotional Lucy-Grace thanks Tom, the only father she knew, for rescuing and raising her for the few years on Janus, and they promise to stay in touch.
DreamWorks acquired the rights to the novel on November 27, 2012, with David Heyman and Jeffrey Clifford producing through Heyday Films. DreamWorks approached Derek Cianfrance at the behest of Steven Spielberg, who was impressed by Cianfrance's Blue Valentine. In September 2013, Cianfrance was announced to direct the film. In May 2014, Michael Fassbender was announced in the film. In June 2014, Alicia Vikander joined the cast of the film. In July 2014, Rachel Weisz joined the cast. Participant Media joined the production in August 2014.
Principal photography started in September 2014, with filming locations in New Zealand and Australia. Filming took place in Dunedin, Port Chalmers and on the Otago Peninsula, Saint Bathans in Central Otago and at the Cape Campbell Lighthouse in Marlborough. Filming sites included the former Dunedin Prison in Dunedin and Stuart Street at the former King Edward Technical College building.
Footage aboard a steam train was filmed in October inside a refurbished wooden "bird cage" passenger carriage from the Pleasant Point Railway in South Canterbury. Mainline Steam Heritage Trust used Ja 1240 "Jessica" for the movie and it was transferred from the trust's Christchurch depot to Dunedin for filming to take place. While the scene in which the locomotive is used was set in 1918, locomotive Ja 1240 was built in 1947 and was the second New Zealand Railways JA class locomotive to be built. Built at New Zealand Railways Hillside workshops in Dunedin it ran exclusively in the South Island of New Zealand from 1947 until 1971.
In November the production moved to Australia and filming began in Stanley, Tasmania where the crews transformed some locations in the town including the pier, which was refurbished, and the road, which was covered in gravel. Production wrapped on November 24, 2014.
Cianfrance spent a year editing the film, with little breaks in between with the first cut of the film ending up at 2 hours and 20 minutes.
The Light Between Oceans held its world premiere at the 73rd Venice International Film Festival on September 1, 2016. The film was distributed by Walt Disney Studios Motion Pictures through the Touchstone Pictures banner, being the last DreamWorks film to be released under the original agreement with Walt Disney Studios. Disney released the film in the United States on September 2, 2016. Disney opted not to give the film a limited release, a method often used by studios for adult dramas, and instead issued the film in general wide release at 1,500 locations with focus on upscale venues.
Disney also distributed The Light Between Oceans overseas, except for territories in Europe, the Middle East and Africa, where distribution was handled by Mister Smith Entertainment through other third-party film distributors; Entertainment One Films in the United Kingdom, Reliance in India, Arthouse in Russia, Eagle Pictures in Italy, and Phantom Film in Japan.
The Light Between Oceans was released by Touchstone Home Entertainment on Blu-ray, DVD, and digital download on January 24, 2017.
The Light Between Oceans grossed $12.5 million in North America and $11.6 million in other territories for a worldwide total of $24.1 million, against a budget of $20 million.
In the United States, the film was released on September 2, 2016, alongside Morgan, and was projected to gross $6–9 million from around 1,500 theaters in its opening weekend. It grossed $1.4 million on its first day and $4.8 million in its opening weekend, finishing 6th at the box office.
The Light Between Oceans received mixed reviews from critics. On review aggregation website Rotten Tomatoes, the film has an approval rating of 59%, based on 184 reviews, with an average rating of 6.2/10. The site's critical consensus reads, "The Light Between Oceans presents a well-acted and handsomely mounted adaptation of its bestselling source material, but ultimately tugs on the heartstrings too often to be effective." On Metacritic, the film has an average score of 60 out of 100, based on 44 critics, indicating "mixed or average reviews". According to CinemaScore, audiences gave the film an average grade of "B+", on an A+ to F scale.