David Irving v Penguin Books and Deborah Lipstadt is a case in English law against American historian Deborah Lipstadt and her British publisher Penguin Books, filed in the High Court of Justice by the British author David Irving in 1996, asserting that Lipstadt had libelled him in her 1993 book Denying the Holocaust. The court ruled that Irving's claim of libel relating to Holocaust denial was not valid under English defamation law because Lipstadt's claim that he had deliberately distorted evidence had been shown to be substantially true. English libel law puts the burden of proof on the defence, meaning that it was up to Lipstadt and her publisher to prove that her claims of Irving's deliberate misrepresentation of evidence to conform to his ideological viewpoints were substantially true.

Deborah Esther Lipstadt is an American historian and diplomat, best known as author of the books Denying the Holocaust (1993), History on Trial: My Day in Court with a Holocaust Denier (2005), The Eichmann Trial (2011), and Antisemitism: Here and Now (2019). She has served as the United States Special Envoy for Monitoring and Combating Anti-Semitism since May 3, 2022. Since 1993 she has been the Dorot Professor of Modern Jewish History and Holocaust Studies at Emory University in Atlanta, Georgia, US.