Dr. John Dalton’s office is almost identical to Ullman’s office in The Shining.
The first hospital room that we see Azzie the cat go into (where Dan comforts a dying patient) is numbered “217.”
Danny Lloyd — who played Danny in The Shining movie — has a cameo during the baseball scene in Iowa.
There are a TON of references to Stephen King’s magnum opus The Dark Tower series. For example, Dick Hallorann tells Dan, “Ka is a wheel,” which is a line straight out of The Dark Tower.
Bradley Trevor’s (the baseball boy) jersey number is 19, which is an important number in The Dark Tower series.
“Tet Transit” — the name of the bus line Dan takes up to NH — is a nod to the Tet Corporation in The Dark Tower series.
And, interestingly, the industrial park that Bradley’s body is buried in is owned by LaMerk Industries — another Dark Tower company.
You can see posters for the musician Joe Collins, aka Dandelo, who is a creature from The Dark Tower.
There are also several callbacks to the book version of The Shining that never made it into Kubrick’s film. For example, when Dan calls Jack/Lloyd a “false face.”
And when Jack/Lloyd tells Dan to “take your medicine.”
The Overlook being destroyed by the boiler is from the book version of The Shining as well.
The Stone family’s house has a sign outside that says “1980” — the year that Kubrick’s The Shining was released.
When we flash forward to 2019 and Dan is at his AA meeting, he’s wearing a light blue sweater that’s the same color as the iconic “Apollo 11” sweater young Danny wears in The Shining.
There were different-colored typewriters used in Kubrick’s movie; for Doctor Sleep they re-created the tan one.
The way Rose approached Dan on the stairs is a total re-creation of Jack approaching Wendy in The Shining.
Dan gets injured and limps around on the same leg that his father did in The Shining.
And finally, Jack Torrance/Lloyd goes uncredited in the movie, but he’s played by Henry Thomas.