Russell's teapot is an analogy, formulated by the philosopher Bertrand Russell (1872–1970), to illustrate that the philosophic burden of proof lies upon a person making empirically unfalsifiable claims, rather than shifting the burden of disproof to others.

Russell specifically applied his analogy in the context of religion. He wrote that if he were to assert, without offering proof, that a teapot, too small to be seen by telescopes, orbits the Sun somewhere in space between the Earth and Mars, he could not expect anyone to believe him solely because his assertion could not be proven wrong.

The analogy has been criticised by philosophers Brian Garvey, Peter van Inwagen and Alvin Plantinga as to its validity regarding religion. Russell's teapot has given rise to similar analogies as well as been used in parodies of religion.