Hypothetical Axis victory in World War II

A hypothetical military victory of the Axis powers over the Allies of World War II (1939–1945) is a common topic in speculative literature. Works of alternative history (fiction) and of counterfactual history (non-fiction) include stories, novels, performances, and mixed media that often explore speculative public and private life in lands conquered by the coalition, whose principal powers were Nazi Germany, Imperial Japan, and Fascist Italy.

The first work of the genre was Swastika Night (1937), by Katherine Burdekin, a British novel published before Nazi Germany launched the Second World War in 1939. Later novels of alternative history include The Man in the High Castle (1962) by Philip K. Dick, SS-GB (1978) by Len Deighton, and Fatherland (1992) by Robert Harris. The stories deal with the politics, culture, and personalities who would have allowed the fascist victories against democracy and with the psychology of daily life in totalitarian societies. The novels present stories of how ordinary citizens would have dealt with fascist military occupation and with the resentments of being under colonial domination.

This subgenre usually focuses on Nazi Germany's supremacy over Great Britain and/or the United States, although The Ultimate Solution, Man in the High Castle and The Divide (novel) all provide some description of life in the Japanese Empire's domination over the Pacific Northwest coast of the former United States. In both The Ultimate Solution and Man in the High Castle, there is a Cold War between the two estranged Axis partners, reminiscent of the equivalent animosity in our world between the United States and Soviet Union, which is threatening to turn into a fully fledged nuclear holocaust. The most detailed discussion of the Japanese Empire's coeval ascendancy is in Man in the High Castle within the occupied Pacific States of America. Cyril Kornbluth's short story "Two Dooms" (1958) also more actively explores the Japanese presence in the defeated and occupied United States. In Man In the High Castle, fascist Italy is relegated to a distant and dependent third place, with derisive mention of its "African empire."

The term Pax Germanica was applied to the hypothetical Imperial German victory in the First World War (1914–1918). The concept is derived from that of Pax Romana and follows the trend of historians coining variants of the term to describe other periods of relative peace, whether established or attempted, such as Pax Americana, Pax Britannica and Pax Sovietica (see pax imperia).

Academics such as Gavriel David Rosenfeld in The World Hitler Never Made: Alternate History and the Memory of Nazism (2005), have researched the media representations of 'Nazi victory'.