Robbie joins the likes of her Wolf of Wall Street co-star Leonardo DiCaprio, Brad Pitt, Kurt Russell and Burt Reynolds in the film, which will be a Pulp Fiction-esque 'tapestry-like' series of stories set in Hollywood in 1969, with the Manson Family murders featuring.
Tate, the wife of Roman Polanski, was murdered by the Manson Family in 1969 when she was 8 months pregnant.
Robbie spoke about the role in an interview with IndieWire, saying: "Tarantino is one of my bucket-list directors. As long as I can remember, I’ve been a huge Tarantino fan.
"Beyond anything, I’ve just always wanted to see him work. And I want to see how he runs a set, and how he directs people, and what the vibe is onset, and what’s in the script, and then what happens on the day. I’m just fascinated by all of it, fascinated. So it’s going to be a crazy experience to witness it firsthand. It’s something I’ve always dreamed of doing."
She added of playing the role of Sharon Tate: "I feel a responsibility with every character I play, whether they’re fictional or real life. To play her right, play her truthfully, and kind of understand her emotional journey."