The Popish Plot is a fictitious conspiracy concocted by Titus Oates that grips England in anti-Catholic hysteria between 1678 and 1681.

Oates alleges that there exists an extensive Catholic conspiracy to assassinate Charles II, accusations that lead to the execution of at least 15 men and precipitates the Exclusion Bill Crisis.

Eventually Oates' intricate web of accusations falls apart, leading to his arrest and conviction for perjury.