Acting career
Poésy's first English-speaking role was in the 2004 BBC miniseries Gunpowder, Treason & Plot, in which she played Mary, Queen of Scots, subsequently winning the 2005 Golden FIPA for actress in a TV Series and Serial.
In 2005, Poésy appeared in the Harry Potter franchise as Fleur Delacour in the fourth film in the series, The Goblet of Fire, a role she reprised in the final two Harry Potter films, released in 2010 and 2011, respectively. Between 2006 and 2007, she appeared in a number of film and television productions, including the 2007 miniseries adaptation of War and Peace.
In 2008, Poésy starred in the Academy Award-nominated black comedy crime thriller In Bruges, alongside Colin Farrell, and Harry Potter co-stars Ralph Fiennes and Brendan Gleeson. The following year, she starred in the 2009 psychological horror film Heartless opposite Jim Sturgess. She also played Chuck Bass's new French girlfriend, Eva, in the fourth season of The CW's hit show Gossip Girl.
In 2010, Poésy appeared alongside James Franco in 127 Hours, directed by Danny Boyle. The film was screened at the Toronto International Film Festival on 12 September 2010, following its premiere at the 2010 Telluride Film Festival. She also starred alongside Rupert Friend in the 2011 film Lullaby for Pi, a romantic drama and Benoit Philippon's directorial debut. The film is about a jazz singer (Friend) whose wife has just died and who meets a mysterious woman (Poésy). Forest Whitaker also starred. Also in 2011, she starred as Jeanne d'Arc in the French historical film The Silence of Joan, directed by Philippe Ramos. The film was screened in the Directors' Fortnight at the 2011 Cannes Film Festival.
Poésy can also be heard singing on the album Colour of the Trap by Miles Kane. She is featured on the track "Happenstance".
In 2012, Poésy starred as Isabelle Azaire in the BBC's adaptation of Sebastian Faulks's novel Birdsong, alongside Eddie Redmayne,, played Queen Isabella in Richard II – the first episode of the BBC TV series The Hollow Crown – and made her Broadway debut in Cyrano de Bergerac as Roxane. She also starred in the short film Hope, directed by Dominique Blanc; the short was part of an eight-film anthology series titled Hopper Stories, commissioned by Arte France and inspired by the artwork of American painter and printmaker Edward Hopper. Hope was inspired by Hopper's 1961 painting A Woman in the Sun. The same year, Poésy appeared in another short film, The Capsule, filmed on the Greek island of Hydra and directed by Athina Rachel Tsangari. In 2013, she starred alongside Michael Caine in the film Mr. Morgan's Last Love, and played Elise Wassermann, the female lead in the Sky Atlantic/Canal+ crime drama series The Tunnel, which comprised 24 episodes over three seasons. Also in 2013, she appeared on stage at the Théâtre La Pépinière in Paris in the play Je Danse Toujours, directed by her father, Étienne Guichard.
In 2015, she appeared in the thriller The Ones Below, directed by David Farr in his feature debut. The film follows follows expectant couple Kate (Poésy) and Justin (Stephen Campbell Moore) as their lives unravel after mysterious new neighbours move into the downstairs flat. The film was screened at the 2015 Toronto International Film Festival, and in the Panorama section at the 66th Berlin International Film Festival, before its release in the United Kingdom on 11 March 2016. In 2017, she played Caroline, the muse and mistress of Alberto Giacometti, in Stanley Tucci’s biographical film Final Portrait, alongside Geoffrey Rush and Armie Hammer, and the following year, played Françoise Gilot in the second season of the biographical anthology drama series Genius, focusing on two periods in the life of Pablo Picasso. In 2019, she portrayed Yelena in Chekhov's Uncle Vanya at the Theatre Royal in Bath, and appeared in Christopher Nolan's 2020 science fiction action film Tenet, alongside her Mr. Morgan's Last Love co-star Michael Caine, and Harry Potter co-star Robert Pattinson.
Poésy also starred as the lead actress in the music video for M. Ward's 2020 single "Unreal City," which was filmed in Paris and directed by Beatrice Pegard. The video features Poésy walking and dancing through the streets of the city, bringing the song's themes to life. The same year, she played Emma, a dedicated French Resistance fighter, in the biographical drama film Resistance, alongside Jesse Eisenberg. Poésy shared that she has a direct link to the era in which the film takes place, because her grandmother fought with the French Resistance during World War II.
In 2022, Poésy played Stella Ransome in the Apple TV+ miniseries The Essex Serpent, and the following year, appeared in the drama film The Last Rifleman, alongside Pierce Brosnan and Jürgen Prochnow. Around this time, she also played Isabelle Carriere, a pragmatic nun, in AMC's post-apocalyptic horror drama series The Walking Dead: Daryl Dixon, and scientist Cécile Dumont in the French/Belgian true crime miniseries Sambre - Anatomy of a Crime. In 2024, she portrayed Matilda of Flanders in the period drama King & Conqueror, which premiered on 24 August 2025 on BBC One.
