Western productions that could be considered Isekai?

[Legarad]

Books: Alice in Wonderland (1865), The Wonderful Wizard of Oz (1900), Peter Pan (1904) , The Chronicles of Narnia (1950

Spoiler

In the Final Book All Characters Protagonist are confirmed dead in Real World but reincarnated in New Narnia World

)

Theathers: The Nutcracker (1980)

These are all that I know, and have the requirement to send or reincarnate the protagonist to another world

 

[Hanbei]

Black Knight (2001) and Army of Darkness (1992) are the first that come to my mind

 

[VanChizzle]

Witch World (1963)

Possibly The Neverending Story (1984) too?

 

[PCN24454]

Zixx, maybe.

 

[McGann]

Infinity Train definitly.
Over the Garden Wall, but with more of a folklore leaning.
Owl House.
Galidor: Defenders of the Outer Dimension was a cool show from years back.
Labyrinth (1986)
Captain N

 

[Rohan]

In Western parlance the "Isekai" genre of fiction is popularly known as "Portal Fantasy".

Portal Fantasy | Best Fantasy Books

 

[VanChizzle]

Jumanji

Guardians of the Flame (1983)

 

[Tortoiseshel]

I'm putting in a vote for my favorite childhood book, The Phantom Tollbooth. It's kinda similar to Alice in Wonderland, a bored kid is spirited away to a strange fantasy world for some weird wacky adventures.

 

[SuperStarlite]

Disney's Amphibia series easily qualifies.

 

[Kit Chan]

Tron
Tron Legacy

 

[Naal]

Maybe A Wrinkle in Time fits too