Jaye Davidson “is best known for his roles as transgender woman “Dil” in the 1992 suspense-drama thriller film The Crying Game,[1] for which she* received an Academy Award nomination for Best Actor in a Supporting Role, making her* the first Black British actor to be nominated for an Oscar”. (quote from Wikipedia)
I’m not certain, but she could have been the first trans-fluid individual to have a starring role in a major film.
*(I changed these pronouns)