Gatsby's alter ego Milo Dukanovic is named after the Prime Minister of Montenegro, while Nick's alter ego Filip Vujanovic is named after the President of Montenegro.
Colin Jacobson was originally cast as Nick's alter ego, Filip Vujanovic, but he was unavailable, so Michael Machiesky was cast instead.
In the original draft, Wilson was the head of West Egg instead of Wolfshiem.
In the scene where Klipspringer shows Gatsby and Daisy his gadgets, he says "I have a special gadget, if you wanna fight." This is a reference to the character Marshal Duncan in Untitled Macbeth Western Project (2015), who always says "You wanna fight?" Both characters are portrayed by Matthew Levenson, and "You wanna fight?" was something Levenson said in real life.