The Australian actress, who has starred alongside the likes of Leonardo DiCaprio in 'The Wolf of Wall Street', reckons that Domhnall Gleeson is one of the best young actors working in Hollywood at the moment.
Robbie has just made the film 'Goodbye Christopher Robin' with Dubliner Gleeson. It is the second time they have worked together in recent years.
"He is unbelievable. He was amazing and he is such an incredible actor. I love the choices he makes with the roles he does. He is very funny and a wonderful person,"Robbie told Bang Showbiz.
"He is the greatest guy in the world. I want to keep working with him forever."
Back in 2013, Robbie starred with Brendan Gleeson's son, alongside Rachel McAdams and Bill Nighy, in 'About Time'.
Last year, she told RTÉ Entertainment: "He's just done the most incredible films and he's just such a nice guy."
Gleeson repaid the compliment, saying: "Margot Robbie is wonderful. She is brilliant to be around and a really good person.
"You want to hold on to those people. I have worked with her twice now and I hope that relationship continues over the years."
Their new movie 'Goodbye Christopher Robin' will be in the cinemas from 29 September.
The film is about legendary writer A.A. Milne who created the famous cartoon character Winnie-the-Pooh. It is directed by Simon Curtis and written by Frank Cottrell-Boyce and Simon Vaughan.