In mid-1920s Copenhagen, portrait artist Gerda Wegener asks her husband, popular landscape artist Einar Wegener, to stand in for a female model who is late coming to their flat to pose for a painting she's working on.
The act of posing as a female figure unmasks Einar's life-long gender identity as a woman, who names herself Lili Elbe. This sets off a progression, first tentative and then irreversible, of leaving behind the identity as Einar, which she has struggled to maintain all her life. This takes place as both Lili and Gerda relocate to Paris; Gerda's portraits of Lili in her feminine state attract serious attention from art dealers in a way that her previous portraiture had not. It is there that Gerda tracks down art dealer Hans Axgil, a childhood friend of Lili (whom Lili had kissed when they were young). Hans and Gerda's mutual attraction is a challenge, as Gerda is navigating her changing relationship to Lili; but Hans' long-time friendship with and affection for Lili cause him to be supportive of both Lili and Gerda.
As Lili's continued existence presenting as male becomes too much to bear, she starts to seek help from psychologists, but none yields any result, and, in one instance, almost leads her to being committed to an asylum. Eventually, at Hans's recommendation, Lili and Gerda meet Dr. Kurt Warnekros. Dr. Warnekros explains that he has met several people like her, who are physically male but identify as female, and proposes a new, innovative, and controversial solution: male-to-female sex reassignment surgery. This would entail a two-part procedure that involves first removing Lili's external genitalia and then, after a period of recovery, fashioning a vagina. He warns Lili and Gerda that it is a very dangerous operation that has never been attempted before, and Lili would be one of the first to undergo it. Lili immediately agrees and, soon after, travels to Germany to begin the surgery.
Lili eventually dies of complications from the surgery. The film ends with Gerda and Hans on a hilltop back in Denmark, in front of the five trees Lili had painted. The scarf that Lili had originally given Gerda, and that had subsequently been given back and forth several times, is carried away on the wind, dancing.
Eddie Redmayne as Einar Wegener / Lili Elbe (Lili Elvenes)
Alicia Vikander as Gerda Wegener (née Gottlieb)
Matthias Schoenaerts as Hans Axgil (Fernando Porta)
Ben Whishaw as Henrik Sandahl (Claude Lejeune)
Amber Heard as Ulla Paulson
Sebastian Koch as Dr. Kurt Warnekros
Pip Torrens as Dr. Jens Hexler
Nicholas Woodeson as Dr. Buson
Emerald Fennell as Elsa
Adrian Schiller as Rasmussen
Henry Pettigrew as Niels
Pixie as Hvappe, the Jack Russell dog