A sister republic was a republic established by the French First Republic or by local revolutionaries during the French Revolutionary Wars. These republics, though nominally independent, relied heavily on France for protection, making them more akin to autonomous territories rather than independent states. This became particularly evident after the declaration of the French Empire, when several states were annexed, and the remaining turned into monarchies ruled by members of the Bonaparte family.

In the history of France, the First Republic, sometimes referred to in historiography as Revolutionary France, and officially the French Republic, was founded on 21 September 1792 during the French Revolution. The First Republic lasted until the declaration of the First Empire on 18 May 1804 under Napoléon Bonaparte, although the form of government changed several times.