The King of Hearts is a character from the book Alice's Adventures in Wonderland by Lewis Carroll. He seems to, when compared to the Queen of Hearts, be the moderate part of the Wonderland government. As an example, when the Queen, who enjoys ordering beheadings, attempts to have Alice executed (charged with being unable to answer who is lying down in front of her) the King of Hearts reminds her that she is only a child.

The King also quietly pardons many of the subjects the Queen has ordered to be beheaded when the Queen is not looking. This guarantees few people are actually beheaded. Nevertheless, when the Queen plays a game of croquet in the story, the only players who remain at the end are himself, the Queen, and Alice.

At the Knave of Hearts' trial, however, where he acts as judge, he is revealed to be quite juvenile, with such lines as, "don't be nervous or I'll have you executed on the spot" to the Mad Hatter, or asking the Duchess's cook irrelevant questions such as, "what are tarts made of?" Between the two of them, the King and Queen appear to present a fairly accurate portrayal of why Wonderland is as childish, reckless and confusing as it is.