- Randall threatens to put his assistant through the shredder. Steve Buscemi once played a character who was killed by a shredder.
- The restaurant Harryhausen's is named after Ray Harryhausen, a stop-motion animator and innovator who specialized in monsters.
- Sully (supposedly) watching Boo get crushed in the garbage compactor is a shot-for-shot homage to Chuck Jones' Feed the Kitty. Most audience members had the same unintended reaction to its Black Comedy.
- At the end, George is seen going into a door with a mallet and a watermelon a la Gallagher.
- When asked if there are any kids in the village, the Snowman quotes the Armour Hot Dogs jingle by responding "Oh, sure. Tough kids, sissy kids, kids who climb on rocks..."
- Doesn't Randall remind you of another Randall from Disney? And it's not just because they have the same name; they have a similar posture, personality and squinting eyes. Roz even looks and acts like Miss Finster.
- The opening credits look a lot like the hand-drawn Disney movies from the '50s and '60s.
- Blink and you'll miss it — when Monsters Inc. starts using laughter as a power source, take a look at the giant display in the doors' room. Did you see the two silhouettes on it? You know, the taller one hitting the other with a hammer?
- With the company now collecting laughter instead of screams, Fungus (Randall's former, abused assistant) happily remarks, "Oh boy, this is great!", sounding exactly like the formerly abused "Flounder", while putting on a set of Groucho Marx nose-glasses.
- Near the end of the movie, Boo shows Sully her Jessie the Yodelin' Cowgirl doll. In the same scene, Nemo has his Early-Bird Cameo.
- Randal is exiled to the same trailer with the Pizza Planet truck parked out front from A Bug's Life. So double reference!
- On the DVD, "Put That Thing Back Where It Came From Or So Help Me" credits everything to Mike, followed by "Mike Wazowski by Mr. and Mrs. Wazowski."
- In the child's room Mike does his comedy routine in near the end, Disneyland attraction posters can be seen on the walls.
- In the Boom Comics sequel, there is a very unexpected third member of the trifecta out to destroy Mike and Sulley. Well, How many people expected to see the return of SID?!?
Shout Out / Monsters, Inc.