The English actor, who plays Finn in the movie, posted some video clips of the pop-up appearances on his Instagram page.
In the first clip, he's seen running through the theater to cheers from the crowd assembled to view the Lucasfilm production.
"Today I did surprise pop ups for opening night audiences in NYC!” Boyega, 23, captions it. "Had an amazing time meeting you all and again thank you for all the support."
The second clip features his telling the delighted audience, "May the force be with you!"
And in the third clip, he speaks to fans at a Brooklyn theater.
"Amazing energy from Brooklyn fans!" the London-born Boyega writes. "I did random pop ups so they had no idea! Some pop ups before the film and some after the film. Love it!"
The Walt Disney Co. owns production company Lucasfilm and ABC News.