Robbie, 28, plays tragic Tate in Quentin Tarantino's highly lauded ninth film, Once Upon a Time in Hollywood, which premiered at Cannes on Tuesday.
The feature chronicles the harrowing story of Charles Manson's Family, who brutally murdered Tate in August 1969 when she was eight-and-a-half months pregnant with her and husband Roman Polanski's first child.
Watch this video to see the trailer for the "brilliant" and film:
Once Upon a Time received rave reviews at the prestigious event with critics deeming it "brilliant" and "shocking".
Brad Pitt and Leonardo DiCaprio star alongside Robbie as two aged Hollywood actors.
Quentin Tarantino seemed to lose his cool with from a female New York Times reporter during a press conference after Wednesday's premiere, after she quizzed him on why Margot had so few speaking lines in the film.
The famous director flatly retorted "I reject your hypothesis" before Robbie jumped in to say her time on screen was "a moment to honour Sharon".
Margot previously told People Magazine she felt an "enormous responsibility" when assuming the role of Tate, and revealed she spoke with the star's friends and family before filming began to understand who she really was.
Hear more of what Margot had to say about her character here: