When William Came: A Story of London Under the Hohenzollerns

is a novel written by the British author Saki and published in November 1913. It is set several years in what was then the future, after a war between Germany and Great Britain in which the former won. The book chronicles life in London under German occupation, and the changes that come with a foreign army's invasion and triumph.

Like Robert Erskine Childers's 1903 novel The Riddle of the Sands, it predicts World War I (in which Saki would later be killed) and is an example of invasion literature, a literary genre which flourished at the beginning of the 20th century as tensions between European nations increased.