The princes' highly recognizable faces (and Harry's iconic red hair) are hidden by their costumes, but in-the-know fans can be on the lookout for one specific scene. Boyega, who plays the former stormtrooper now known as Finn, says they appear guarding him in an elevator along with two other famous stormtroopers -- actor Tom Hardy and Gary Barlow from British pop group Take That.
"It was a great experience," Boyega said of the scene with the princes, who are second- and fifth-in-line for the British throne. The London-born actor also called the elevator moment "the best of both worlds for me."
There've been plenty of celebrity cameos in the Star Wars saga to date -- enough that we put together an. Recently, James Bond star Daniel Craig also in 2015's "The Force Awakens."
"The Last Jedi" opens Dec. 15.