''The Cat in the Hat'' is a children's storybook written and illustrated by Creator/DrSeuss in 1957, which started off his series of books for beginning readers. The story opens on two children who are stuck inside their house due to rain while their mother is out, when they suddenly get a visit from the eponymous character, a six-foot-tall cat who wears a [[NiceHat tall striped hat]]. The Cat offers to entertain them by performing various tricks, with help from his funny-looking assistants, Thing One and Thing Two, despite the objections from the kids' pet fish. Eventually, after the Cat and the Things end up making a mess of the house, the kids take control of the situation, and the Cat makes up for it by cleaning the place on his way out right before the mother returns.

The Cat became one of Dr. Seuss' most enduring characters, returning the following year in a {{sequel}} titled ''The Cat in the Hat Comes Back'', in which he leaves a "cat ring" in the bathtub and spends the rest of the book spreading the spot around in an attempt to get rid of it. In addition, he hosted three other books by Seuss and also served as the narrator for the otherwise unrelated ''Daisy-Head Mayzie'' (published after Seuss' death).

It got [[WesternAnimation/TheCatInTheHat adapted]] in 1971 by [=DePatie-Freleng=] Studios which expands upon the storyline. It was followed up with ''Creator/DrSeuss On the Loose'' (in which the Cat introduced animated adaptations of ''Literature/TheSneetches'', ''The Zax'', and ''Literature/GreenEggsAndHam'') and ''WesternAnimation/TheGrinchGrinchesTheCatInTheHat'' (in which the Cat matches wits with the title character of ''WesternAnimation/HowTheGrinchStoleChristmas''). The Cat later starred in puppet form in ''TheWubbulousWorldOfDrSeuss''. The original book also got a LivingBooks title.

It was [[Film/TheCatInTheHat adapted to film]] in 2003, but got critically panned, especially by the Geisel estate that no longer gives support for live-action adaptations for Dr. Seuss films.There is apparently an animated reboot [[http://www.deadline.com/2012/03/dr-seuss-the-cat-in-the-hat-get-new-life-at-chris-meledandris-illumination/ in production]] at [[WesternAnimation/DespicableMe Illumination]] [[WesternAnimation/TheLorax Entertainment]], effectively putting the live action film under CanonDiscontinuity.

Is currently starring in the EdutainmentShow ''WesternAnimation/TheCatInTheHatKnowsALotAboutThat'' on PBS.
!!The books contain examples of:

* AnAesop: A little silliness and mischief is fine, as long as you don't take it too far.
* ConstrainedWriting: It was written using a specific constrained vocabulary consisting only of words you'd expect a six-year-old to know.
* MatryoshkaObject: The Cat has Little Cat A under his hat, who has Little Cat B under its hat and so forth. [[spoiler:Underneath Cat Z's hat is the "Voom", which unleashes some kind of divide by zero effect only for when the GodzillaThreshold has been reached (in the case, cleaning up the yard.)]]
* NoNameGiven: The boy who narrates the story is never given one.
** Ditto for the cat himself (as well as that fish).
* OnlySaneMan: The Fish.
* OrderVersusChaos: The Cat is a TricksterArchetype {{Ubermensch}} who calls for tearing down the old social order. His foil is a fish who insists on maintaining respect for traditional authority figures.
* PersonWithTheClothing
* RainRainGoAway
* ResetButton: Before he leaves, the Cat always manages to undo all the damage he's caused.
* ScrewySquirrel: The Cat.
* ScreenToStageAdaptation: A stage version of the book was shown in London sometime in 2011 and was even available on Netflix at one point.