During the early stages of the COVID-19 pandemic, a number of non-pharmaceutical interventions, particularly lockdowns, were implemented in numerous countries and territories around the world. These restrictions were established with the intention to reduce the spread of SARS-CoV-2, the virus that causes COVID-19. By April 2020, about half of the world's population was under some form of lockdown, with more than 3.9 billion people in more than 90 countries or territories having been asked or ordered to stay at home by their governments. Although similar disease control measures have been used for hundreds of years, the scale of those implemented in the 2020s is thought to be unprecedented.

A curfew is an order that imposes certain regulations during specified hours. Typically, curfews order all people affected by them to remain indoors during the evening and nighttime hours. Such an order is most often issued by public authorities, but may also be given by the owner of a house to those living in the household. For instance, children are often given curfews by their parents, and an au pair is traditionally given a curfew by which time he or she must return to his or her host family's home. Some jurisdictions have juvenile curfews which affect all persons under a certain age not accompanied by an adult or engaged in certain approved activities.