Having trained in contemporary dance at the Lille Conservatory, Adeline d'Hermy turned towards the theatre. She was admitted into the Cours Florent in 2006, having won a place at the competition for the Classe Libre. In 2009, she passed with flying colors the entrance exam for the Paris Conservatory where she trained with Alain Françon and Dominique Valadié. The same year, she played in Feydeau’s Le Dindon directed by Fanny Sidney. The following year at the Conservatory, she danced in a show by Caroline Marcadé inspired by Molière and entitled Un amour d'Agnès, she then played Natasha in Chekhov’s Three Sisters directed by Julien Olivieri.

Having been admitted into the Comédie-Française as a pensionnaire on the 9th of December 2010, Adeline d’Hermy made her debut there as Phénice in Racine’s Bérénice under the direction of Muriel Mayette-Holtz. She has been cast in both classical and contemporary roles, and has interpreted Jeanne in Marguerite Duras’s La Pluie d'été directed by Emmanuel Daumas; Rosina in Carlo Goldoni’s The Villegiatura Trilogy (La Trilogie de la villégiature) by Alain Françon; Nonancourt’s daughter Hélène in Labiche’s An Italian Straw Hat (Un chapeau de paille d'Italie) by Giorgio Barberio Corsetti; Annette in Jules Renard's Poil de carotte by Philippe Lagrue; Helena in Shakespeare’s A Midsummer Night’s Dream by Muriel Mayette-Holtz; Silvia in Marivaux’s The Double Inconstancy (La Double Inconstance) by Anne Kessler; Princess Negroni in Victor Hugo’s Lucrezia Borgia by Denis Podalydès. Éric Ruf entrusted her with several roles in his staging of Ibsen’s Peer Gynt while Lilo Baur asked her to play Adela in The House of Bernarda Alba by Federico Garcia Lorca.
Directors have often called on her to play in comedies by Molière: Jean-Pierre Vincent gave her the role of Charlotte in Don Juan or the Feast with the Statue (Dom Juan ou le Festin de pierre), Jacques Lassalle envisaged her as Agnès in The School for Wives (L’École des femmes), Clément Hervieu-Léger first offered her the role of Éliante in his staging of The Misanthrope before casting her as Célimène when the play was rerun.

Adeline d'Hermy became sociétaire on the 1st of January 2016, and was first directed by Alain Françon in Edward Bond's The Sea and later by Ivo van Hove in The Damned (Les Damnés), his adaptation of Luchino Visconti’s screenplay. In 2017, she played Zerbinette in Molière's Les Fourberies de Scapin as directed by Denis Podalydès. Anne Kessler entrusted her for Tekla’s role in August Strindberg’s The Creditors (Les Créanciers)

Adeline d’Hermy made her cinema debut in 2008 in Je ne suis pas morte by Jean-Charles Fitoussi. In 2014, Jalil Lespert entrusted her with the role of Anne-Marie Munoz in the biopic Yves Saint-Laurent. In 2017, she played the title role in Guillaume Gallienne’s Maryline.