Alma Pöysti (born Alma Ilona Pöysti on March 16, 1981, in Helsinki) is a Swedish-speaking Finnish actress. Coming from an artistic family, she is the daughter of director Erik Pöysti and the granddaughter of actors Lasse Pöysti and Birgitta Ulfsson.

A 2007 graduate of the Theatre Academy of Helsinki, she began her career on stage at the Swedish Theatre in Helsinki and the Finnish National Theatre, while also performing in Sweden.

She gained international recognition playing artist and author Tove Jansson in the biographical film Tove (2020), a role that earned her the Jussi Award for Best Leading Actress. She won a second Jussi Award for her performance in Four Little Adults (Neljä pientä aikuista, 2023).

Her international profile grew further with the lead role of Ansa in Aki Kaurismäki's Fallen Leaves (Kuolleet lehdet, 2023), a film awarded the Jury Prize at the Cannes Film Festival and for which she received a Golden Globe nomination for Best Actress in a Motion Picture – Musical or Comedy. Her filmography also includes the Swedish feature A Day and a Half (En dag och en halv, 2023) and the film Sukkwan Island (2025), as well as the television series Helsinki Syndrome, Harjunpää, and Blackwater (Händelser vid vatten).