According to The Hollywood Reporter, the actor, who has featured in shows such as Romper Stomper, The Cry and Picnic at Hanging Rock, will portray the role of Tyra.
Further details of her character are yet to be revealed.
The streamer had recently announced that Jurrasic World: Fallen Kingdom helmer JA Bayona will be directing the first two episodes of the show.
He will also serve as executive producer alongside partner Belen Atienza.
Bryan Cogman, who worked as a writer and co-executive producer on Game of Thrones, also boarded the project as a series consultant. He is helping out the writing team of Patrick McKay and JD Payne, who were announced as series developers last year.
Amazon has made a multi-season production commitment to the TV series. It will produce the show in cooperation with the Estate of J R R Tolkien, publishing house HarperCollins, and New Line Cinema, a division of Warner Bros.
However, the series will not be a retelling of Peter Jackson’s Oscar-winning trilogy. It will explore story set before the events in the first LOTR novel, The Fellowship of the Ring.