In August 2005, Daisy Fuller is on her deathbed in a New Orleans hospital. She tells her daughter Caroline about blind clockmaker Mr. Gateau, hired to make a clock for a train station in 1918. It ran backwards and was made as a memorial for those who lost their sons in World War I, like Gateau himself. Daisy then asks Caroline to read aloud from Benjamin Button's diary.
On the evening of November 11, 1918, a boy is born with the appearance and maladies of an elderly man. His mother, Caroline, dies soon after childbirth and his father, wealthy manufacturer Thomas Button, abandons him on the porch of a nursing home. Caretaker Queenie and cook Mr. Weathers find the baby, and Queenie raises him as her own, naming him Benjamin. As the years pass, Benjamin physically blends in with the elderly residents but has the mind of a child. Physically aging in reverse, he transitions from a wheelchair to crutches and learns to walk.
On Thanksgiving 1930, Benjamin meets seven-year-old Daisy, whose grandmother lives in the nursing home, and they connect instantly. Later, he accepts work on the tugboat Chelsea captained by Mike Clark. Thomas introduces himself to Benjamin, but does not reveal his true identity. In autumn 1936, Benjamin leaves for a work engagement with the tugboat crew and travels around the world. He sends postcards to Daisy, who is accepted into a ballet company in New York City.
In Murmansk in 1941, Benjamin becomes smitten with Elizabeth Abbott, wife of the chief minister of the British trade mission in Murmansk.[5] Their affair eventually ends, leaving Benjamin heartbroken. That December, the United States enters World War II. Mike volunteers the Chelsea for U.S. Navy service, and they are assigned to salvage duties. They find a near sunken U.S. transport and thousands of dead American troops. The culprit, a German U-boat, surfaces and fires on the tugboat. Captain Mike rams the submarine and the resulting explosion sinks both. Most of the crew perishes except for Benjamin and Rick Brody, who are eventually rescued.
In May 1945, Benjamin returns to New Orleans, reuniting with Queenie and learns that Weathers died. He reconnects with Daisy, who attempts to seduce him. However, Benjamin refuses, and she departs. Benjamin visits terminally ill Thomas and learns the details of his birth and family. Thomas gives his button manufacturing company and estate to Benjamin before dying.
In 1947, Benjamin visits Daisy in New York unannounced but departs upon seeing her romantically involved with someone else. In 1954, Daisy's dancing career ends when her leg is crushed in an automobile accident in Paris. When Benjamin visits her, Daisy is amazed by his appearance, but, frustrated by her injuries, she tells him to stay out of her life.
In 1962, Daisy returns to New Orleans and reunites with Benjamin. Now of comparable physical age, they fall in love. Queenie dies, and Benjamin and Daisy move in together. In 1967, Daisy, who has opened a ballet studio, announces she is pregnant. Their daughter, Caroline, is born in the spring of 1968. Believing he cannot be a proper father due to his reverse aging, Benjamin sells his assets, leaves the money for Daisy and Caroline, and leaves to travel alone during the 1970s.
Benjamin, physically a young man, returns to Daisy in 1980. Now married, Daisy introduces him as a family friend to her husband Robert and Caroline. She later visits him at his hotel, where they have sex and part once more. In 1990, recently widowed Daisy is contacted by social workers who found Benjamin, who is now physically a pre-teen. He was living in a condemned building, was taken to the hospital in poor physical condition, and his diary had her name in it. Benjamin displays early signs of dementia, so Daisy moves into the nursing home in 1997 and cares for Benjamin for the rest of his life as he regresses into infancy.
In 2002, Gateau's clock is replaced with a properly working modern digital clock and in 2003, Benjamin dies in Daisy's arms, physically an infant but chronologically over 84 years old. Back in 2005, having revealed that Benjamin is Caroline's father, Daisy dies. Hurricane Katrina floods a storage room holding Gateau's clock, which keeps ticking backwards.
