David Geselson trained at the National Conservatory. After graduating in 2003, he initially invested himself in his work as an actor. Then, in 2009, he directed Les Insomniaques, a text by Juan Mayorga. Since then, he has been involved in all aspects of the dramatic arts.

In the cinema, he has acted under the direction of Élie Wajeman (Alyah, 2012, Les Anarchistes, 2015) and Isabelle Czajka (La Vie Domestique, 2013). He also played the role of Élie in the television series Ainsi soient-ils (2014). In the theatre, he regularly acts under the direction of Tiago Rodrigues (Bovary, 2016, Chœur des Amants, 2020).

As a director, he founded the company Lieux-Dits in 2009. Under his direction, history and biographical narratives are the starting point for fictions written specifically for the players. In 2014, he created En Route-Kaddish, a play for which he wrote and reinvented the story of his grandfather based on archives and family stories. With Doreen in 2016, he dramatises the love of André Gorz and his wife Dorine Keir.

David Geselson's work is marked by extensive research prior to writing his plays. He travels, conducts readings and collects testimonies. His creations are also informed by collaborative research on the stage, offering a fictionalisation of this documentary material. This long process allows him and his actors to develop a shared unconsciousness.

Geselson has made a name for himself as a playwright, but also as an author. Since 2017, he has put his writing at the service of spectators who want to give flesh to their thoughts, for which they have never before found the words or put pen to paper. This practice gave rise to the show Lettres Non Écrites (2017), and then to the collection of texts of the same name, published in the spring of 2021.

David Geselson is an associate artist at the Théâtre de l'Aquarium, the Théâtre de Lorient, the CDN and Le Grand R National Theatre.

In 2020, he will create Le Silence et la Peur, based on the figure of Nina Simone. Through her, he addresses four centuries of colonial domination in the United States. He summons the legacies of his artists to the stage to share them with the audience. The casting of the play sent him to New York, where he began a collaboration with the African-American actress Dee Beasnael.

In the summer of 2021, Geselson again acted under the direction of Tiago Rodrigues, alongside Isabelle Huppert. Their interpretation of La Cerisaie (The Cherry Orchard) is presented in the main courtyard of the Palais des Papes during the Avignon Festival.