Produced by Chuck Jones at MGM Animation/Visual Arts, the film stars Butch Patrick as Milo, alongside the voice talents of Mel Blanc, Daws Butler, Candy Candido, Hans Conried, June Foray, Patti Gilbert, Shepard Menken, Cliff Norton, Larry Thor, and Les Tremayne.

One day while telling his friend over the phone that there's "no rhyme or reason" in his life, he is surprised by a large, gift-wrapped package that appears in his room.

Together, they must rescue the Princesses of Sweet Rhyme and Pure Reason, who are being held captive in the Castle in the Air, and restore order to the Kingdom of Wisdom.

The many eccentric characters they meet include the Whether Man, the Humbug, the Spelling Bee, the noisy Dr. Kakofonous A. Dischord, King Azaz the Unabridged, the Mathemagician, Faintly Macabre the Not-So-Wicked Which, Chroma the Great, and Officer Short Shrift as well as demons like the Senses Taker, the Terrible Trivium, the Demon of Insincerity, and the Gelatinous Giant.

The film ends with a song about Milo finding things to do and being happy within the real world and shows him smiling while playing at a playground.

[7] Charles Champlin of the Los Angeles Times wrote that the film "is a lively and warming enchantment with real appeal for the 7-plus age group—and the plusses run up well into adulthood.

In conclusion, he stated "The youthful viewer and his parents should overlook Phantom Tollbooth's flaws and concentrate on the film's underlying moral.

[10] TV Guide rated it three stars out of four and described it as "a charming film that combines some fairly sophisticated ideas [...] with cute and likable characters that are sure to grab a child's attention".

[11] Tom Hutchinson of the Radio Times rated it 4/5 stars and wrote that the film has "wonderful ideas", but they are "likely to be a bit above the heads of very young children".

"[14] In February 2010, director Gary Ross began development of a live-action remake of The Phantom Tollbooth for Warner Bros., the current owner of the film.

[17] In December 2017, TriStar Pictures picked up the project, and it was announced that Matt Shakman would direct its upcoming "live-action/hybrid" film adaptation of The Phantom Tollbooth with a screenplay by Michael Vukadinovich and Phil Johnston.