The Sons of Liberty were a secretive, loosely organized group of American colonists formed around 1765 to oppose British rule and taxation, especially the Stamp Act. They played a major role in arousing colonial resistance that led to the American Revolution. Notable leaders included Samuel Adams, John Hancock, and Paul Revere. The group used protests, intimidation, and sometimes violence to disrupt British authority in the colonies, with their most famous action being the Boston Tea Party in 1773.

The group's name came from a British Parliament speech by Isaac Barré in 1765, who called colonists opposing unjust British laws "sons of liberty." The Sons of Liberty often met in secret, such as under Boston's "Liberty Tree," and organized acts like public rallies, boycotts, and the destruction of property related to British tax enforcement. They served as a catalyst for united colonial action against "taxation without representation".

Several future American Revolution leaders were among the Sons of Liberty, and the organization was instrumental in mobilizing popular support against British policies until the Revolution officially began and they disbanded in favor of more formal political bodies.