- Beam Me Up, Scotty!: The Chew Bubblegum line often gets switched up to "I'm here to kick ass and chew bubblegum". Funnily enough, Piper himself was guilty of this at WWE's 1994 King of the Ring PPV.
- Prop Recycling: The PKE Meter from Ghostbusters (1984) is used as an alien communication device.
- Throw It In!:
- The famous "Chew Bubblegum" line was, in fact, an adlib by Roddy Piper. The stage directions amounted to "You walk into a bank. You have a shotgun. You're not here to rob it. Say something."
- There's also the very, very long fist fight between Nada and Frank. It was supposed to be cut down, but the creators enjoyed the fight so much, they decided to leave the whole thing in.
- The entire fist fight scene was always intended to be ad-libbed. Carpenter's shooting script simply said "FIGHT CONTINUES" for six pages, having the two actors do their thing.
- During said fight, they also really hit each other. The only thing faked were the face and nut shots.
- What Could Have Been: The role of John Nada was originally written for Kurt Russell. John Carpenter felt he should cast somebody else after casting Russell in three of his films prior to this one (Escape from New York, The Thing and Big Trouble in Little China).
- Word of God: For some reason, racists like to use this movie as an allegory for the alleged international Jewish conspiracy to take over the world. This prompted an exasperated John Carpenter to come out on Twitter and give them all a telling-off.
John Carpenter: THEY LIVE is about yuppies and unrestrained capitalism. It has nothing to do with Jewish control of the world, which is slander and a lie.