A nameless man set adrift by a storm wakes up on a deserted island. Finding fresh fruit and water, as well as variety of small animals and a dense bamboo forest, the man decides to leave the island. The man builds a raft from bamboo, and attempts to sail away. However, an unseen sea creature destroys the raft, forcing the man back to the island. Attempting to escape with another raft, his plan is foiled again by the sea creature. Trying a third time his raft was again destroyed, but once in the water he finds a female red turtle facing him. The turtle does not harm the man, and the man retreats back to the island.
That evening, the man sees the red turtle crawling on the shore, attempting to go inland. In revenge, he hits the red turtle on the head with a bamboo stick, and pushes it over on its back. After halfway through building another raft, the man starts to feel guilty about leaving the turtle upside down, so he catches a fish and tries to feed it to the turtle, but finds that it has died. The turtle's shell splits down the middle during the night, and to the man's surprise, the turtle turns into a woman. The man tries to revive her, making a shelter over her to protect her from the sun. When rain hits the island, the woman wakes up. The man notices she has gone, and searches the island for her, finally seeing that she is on the coastline. Giving her his shirt, he eventually sees the woman dragging the now empty turtle shell into the sea. The man does the same with his half-built raft. The two soon form a strong and enduring romance.
Some years later, the couple have a son who finds a bottle washed up on shore. After accidentally falling into a small cavern, the son forms a peculiar relationship with other turtles in the ocean. Growing up, the son grows accustomed to the island. When he goes into the island for fresh water with his bottle, a tsunami hits the island. Though no one is severely hurt, the island's forest is nearly demolished by it. After burning the remains of bamboo, the son finds his bottle in an oasis in the island. Deciding to leave the island, the son bids his parents farewell, and swims away with a trio of green turtles.
Growing old together, the man and woman spend the rest of their lives on the island. The man dies peacefully one night while looking at the moon. With her work done, the woman holds the man's hand one last time, and transforms back into the red turtle he had met all those decades ago, and returns to the sea.
The film was co-produced by Wild Bunch and Studio Ghibli in association with Why Not Productions. According to Vincent Maraval, head of Wild Bunch, he visited Studio Ghibli in Japan in 2008 and met with Hayao Miyazaki. Miyazaki showed him the short film Father and Daughter and asked him to find its director, Michaël Dudok de Wit, with the prospect of co-producing a feature film. Wild Bunch approached Dudok de Wit in London and convinced him to take on the project. The screenplay was written by Dudok de Wit and Pascale Ferran.
The film premiered on 18 May at the 2016 Cannes Film Festival, where it competed in the Un Certain Regard section. On 13 June, it was screened as the opening film of the 2016 Annecy International Animated Film Festival. The regular French release was 29 June 2016. It was released in Japan on 17 September 2016. In May 2016, Sony Pictures Classics acquired the North and Latin American distribution rights for the film and was released in the United States on 20 January 2017. The Red Turtle was played in the London Film Festival on 5 October 2016 and eventually released internationally by StudioCanal on May 26th 2017.
The Red Turtle received critical acclaim. On review aggregator website Rotten Tomatoes, the film has a 94% score based on 107 reviews, with an average of 8.1/10. The site's critical consensus reads, "The Red Turtle adds to Studio Ghibli's estimable legacy with a beautifully animated effort whose deceptively simple story boasts narrative layers as richly absorbing as its lovely visuals." Metacritic reports a 86 out of 100 rating, based on 30 reviews, indicating "universal acclaim".