Ammonite is a 2020 romantic drama film written and directed by Francis Lee. The film is loosely inspired by the life of British palaeontologist Mary Anning, played by Kate Winslet. The film centres on a speculative^[5] romantic relationship between Anning and Charlotte Murchison, played by Saoirse Ronan. Gemma Jones, James McArdle, Alec Secăreanu and Fiona Shaw also star.

The film had its world premiere at the Toronto International Film Festival on 11 September 2020. It was released in Australia on 14 January 2021 by Transmission Films and in the United Kingdom on 26 March 2021 by Lionsgate.

In the 1840s, fossil collector Mary Anning lives with her ailing mother Molly, who helps Mary run a small shop in Lyme Regis, Dorset. Mary spends the early mornings on the beach at low tide in search of fossils for the shop, with tiny ammonites being her most common find. When she returns, she helps her mother wash and polish a collection of eight animal figurines.

One day, geologist Roderick Murchison visits Mary's shop with his wife, Charlotte. He expresses admiration for Mary's work and offers to pay her for a guided trip to the shore where he can learn from Mary about fossil collecting. While initially antagonistic, Mary accepts his offer. That night in their room at the Three Cups Hotel, Roderick treats Charlotte coldly, rebuffing her sexual advances and saying that now is not the time to have another baby.

Roderick returns from his morning trip with Mary and finds Charlotte confined to her bed in a depressed state. He returns to Mary's shop and reveals that Charlotte has been sent to Lyme Regis in order to convalesce, and entrusts her to Mary's care as he will be departing to Europe for four to six weeks. Mary reluctantly agrees, not wanting to pass up the money. Charlotte begins going out with Mary on her morning beach trips.

After bathing in the ocean as part of her rehabilitation, Charlotte falls ill with a high fever. Her physician, Dr. Lieberson, prescribes bed rest and assigns Mary to be her bedside nurse. Mary visits her friend Elizabeth Philpot, from whom she purchases a jar of salve to aid Charlotte's recovery. Mary refuses Elizabeth's friendly offer to come in for a visit. Charlotte quickly recovers, and from then on accompanies Mary on more outings and tries to help with domestic chores. Together with Mary, she is able to construct a mirror frame made of cowries. Saddened by her own failed attempts to have a baby, Charlotte learns that the figurines which Molly cleans every day represent her eight deceased children.

Dr. Lieberson visits the shop and invites Mary to an evening recital. Mary accepts but insists on bringing Charlotte as well, whom she believes has made a full recovery. That night, Charlotte meets and mingles with the townsfolk as an overwhelmed and jealous Mary smokes outside in the rain while watching through the window. They watch a magic lantern show set to music before Mary leaves and returns home during the rainstorm. Charlotte arrives soon after and finds Mary writing a romantic poem in her journal.

Using the boards from a beached boat, Mary and Charlotte transfer a large rock to the shop. Inside, they find the fossil of an Ichthyosaur similar to one which Mary found when she was aged 11 and sent to the British Museum. As they clean Mary's tools in preparation before going to bed, Charlotte kisses Mary goodnight; this inflames their attraction to one another, and they engage in oral sex. Their relationship blossoms, as they swim in the sea and share their meals. A letter arrives from Roderick, instructing Charlotte to return to London. Distraught, Charlotte and Mary have passionate sex the night before Charlotte's departure. Sometime later, Molly suffers a fall at home and dies soon afterwards. Elizabeth visits the depressed Mary to express her condolences. She encourages Mary to not abandon her relationship with Charlotte, as Mary did with their own romantic relationship after the death of Mary's father.

Mary receives a letter from Charlotte asking her to come to London. Upon arriving at the Murchison house, Mary sees one of her large ammonite fossils on display in a glass cabinet. Charlotte takes Mary upstairs, where she shows Mary a fully furnished bedroom ready for her to move into. Perturbed, Mary leaves after accusing Charlotte of not respecting her life, stating she will not become an ornament for Charlotte to display in a "gilded cage."

At the British Museum, Mary makes her way through the galleries. She finds the exhibit case containing her original Ichthyosaurus but sees that it makes no mention of her. Charlotte arrives dressed in clothes similar to Mary's, and the two women gaze at each other through the glass.

• Kate Winslet as Mary Anning
• Saoirse Ronan as Charlotte Murchison^[6]
• Fiona Shaw as Elizabeth Philpot
• Gemma Jones as Molly Anning
• James McArdle as Roderick Murchison
• Alec Secăreanu as Dr. Lieberson
• Claire Rushbrook as Eleanor Butters

In December 2018, it was announced Kate Winslet and Saoirse Ronan had joined the cast of the film, with Francis Lee directing the screenplay he wrote. Iain Canning, Fodhla Cronin O'Reilly and Emile Sherman serve as producers with See-Saw Films, BBC Films and the British Film Institute.^[7] In March 2019, Fiona Shaw announced her role in the film.^[8] In May 2019, it was announced Alec Secăreanu, James McArdle and Gemma Jones had joined the cast of the film.^[9]

Principal photography began on 11 March 2019, in Lyme Regis, Dorset.^[10][11][12] The scenes were shot chronologically in order to deepen the immersion in the characters' psychological trajectory.^[13] David Tucker, director of the Lyme Regis Museum, consulted on the film's scientific accuracy.^[14]

In February 2019, Lionsgate and Transmission Films acquired UK and Australian distribution rights to Ammonite, respectively.^[15] In January 2020, Neon acquired US and Canadian distribution rights to the film for $3 million.^[16] Ammonite was set to world premiere at that year's Cannes Film Festival, prior to its cancellation due to the COVID-19 pandemic.^[17] It was also selected to screen at the Telluride Film Festival in Colorado in September of that year, prior to its cancellation also due to the pandemic.^[18]

Ammonite had its world premiere at the Toronto International Film Festival on 11 September.^[19] Winslet was awarded TIFF's Tribute Actor Award.^[20][21] Ammonite has or is scheduled to be screened at several film festivals including Deauville,^[22] Hamptons,^[23] Mill Valley,^[24] Newfest,^[25] Ghent,^[26] London,^[27] Chicago^[28] and Montclair.^[29]

Ammonite was theatrically released in the United States on 13 November.^[30] It was subsequently released in Australia on 14 January 2021^[31] and in the United Kingdom on 26 March 2021.^[32]