The role will see the Maynooth native return with original cast members Anjana Cassan, Patsy Ferran and Dwane Walcott for a six week run next Spring.
The Normal People star will reprise his role of Stanley, the husband of Cassan's character whose sister Blanche comes to live with the married couple, before slowly losing her grip on reality.
News of Mescal's West End return comes barely 24 hours after the actor earned his first ever Oscars nightmare, after he was nominated for Best Actor for his performance in Aftersun.
