Napoleon Disentimed is a science fiction novel by American writer Hayford Peirce, first published by Tor Books in 1987.

It is a humorous treatment of two standard science fiction themes, those of time travel and of parallel universes.

In another, the British royal family made different dynastic arrangements, leading to the birth of a male heir to King William IV rather than Queen Victoria, Frederick I, whose descendants still rule the United Kingdom- Frederick IV is the reigning monarch in its 1987.

Through a complicated series of misadventures MacNair ends up impersonating Napoleon Bonaparte for the dictator's so-called "Missing Years", 1806–1808.

By the end of the book he has succeeded in not only acquiring a beautiful wife and a slightly run-down château in France but in also inventing both the modern indoor flush toilet and Champagne.