Gosling praised the former One Direction singer for his “professionalism” before going on to plug his new movie.
He said: “Yeah, that’s so professional, that’s awesome you’re here. I just wish someone would have told me.
“I have a new movie coming out, it’s called Project Harry Styles. Nope – it’d be a good movie, though. … And people are saying it’s like E.T. meets Interstellar, which is crazy because those are like, what, two of the best films of all time, so they’re kind of like saying it’s like, what, double that? I don’t know, I didn’t say it.
“I’ve always loved making films about space. It’s just something about them gives me perspective.”
But he trailed off before the camera panned over to Styles.
He asked: “I’m sorry, why are we on Harry’s side?”
Styles replied: “I don’t know, I’m just listening.”
Gosling quipped: “Well, could you listen less cool? I think your coolness is becoming a bit of an issue.”
Later in his monologue, a group of dancers dressed as aliens appeared to ask if they will perform their planned number, to a song from Project Hail Mary, and Gosling promised they would.
He said: “It’s very poignant and it’s the anthem of our generation. Some have said it’s called Sign of the Times, and oh my God, it’s by Harry Styles. Now I gotta sing it in front of him.”
Gosling began singing a hesitant rendition of the song before turning to perform the I’m Just Ken lyrics from Barbie.
Gorillaz were musical guests on this week’s SNL but Styles will perform double duty as both host and musical guest next week.
