伦敦大瘟疫是一场1665年至1666年间发生在英国的大规模传染病爆发，超过10万人死于这次瘟疫之中，足足相当于当时伦敦人口的五分之一。该次的疾病后来被确认为是淋巴腺鼠疫，一种由鼠疫杆菌造成并以跳蚤为载体的细菌感染。伦敦大瘟疫与1347年至1353年期间侵袭全欧洲，并导致最少7,500万人死亡的黑死病相比规模要小得多，这场前后扰攘大约一年的流行病被人们形容为大灾难的原因，很大程度是由于它已经是英国本土最后一次广泛蔓延的鼠疫，之后随着英国政府着手改善地区卫生条件，鼠疫对英国民众的威胁也逐渐消失。

The Great Plague, lasting from 1665 to 1666, was the last major epidemic of the bubonic plague to occur in England. It happened within the centuries-long time period of the Second Pandemic, an extended period of intermittent bubonic plague epidemics which began in Europe in 1347, the first year of the Black Death, an outbreak which included other forms such as pneumonic plague, and lasted until 1750.