A happy ending is an ending of the plot of a work of fiction in which most everything turns out for the best for the hero or heroine, their sidekicks, and just about everyone but the villains. The prince gets the princess and, in the traditional phrase from fairy tales, they all live "happily ever after."

The presence of a happy ending is one of the key points that distinguishes melodrama from tragedy. In certain periods, the endings of traditional tragedies such as Macbeth or Oedipus Rex, in which most of the major characters end up dead, disfigured, or discountenanced, have been actively disliked. In the eighteenth century, the Irish author Nahum Tate sought to improve Shakespeare's King Lear by rewriting the ending so that Lear survives, Cordelia and Edgar marry, and the three sisters are reconciled. Most subsequent critics have not found Tate's amendments an improvement. Happy endings have also been fastened to Romeo and Juliet and Othello.

In the modern world, happy endings have sometimes been viewed as an American specialty, and the English-language words happy ending (or happy end) have been imported as-is into other languages to make this point. In the 1928 Austrian operetta, Die Herzogin von Chicago, the two lovers who are too proud to speak to one another are finally brought together by a Hollywood producer who explains that he plans to make a movie of their love story, but that he cannot, until it has the required happy ending.

Some works of fiction, most notably Kurt Weill and Bertolt Brecht's operetta The Threepenny Opera, have intentionally implausible happy endings.

The Happy Ending is a 1969 motion picture.