Jean Bailly was a French astronomer and politician. After studying the moons of Jupiter and writing a five-volume history of astronomy (1775–1787), he turned to politics. Out of all proportion to his importance to astronomy, the largest crater on the nearside of the Moon is named after him.

Bailly was born in Paris in 1736 and became a prominent figure in the early years of the French Revolution. He was a member of the National Assembly and served as the first mayor of Paris (1789–1791) after the fall of the Bastille in 1789. He was a member of the French Academy of Sciences and served as its president from 1785 to 1793. Bailly was also a member of the Royal Society in London and was elected as a foreign member of the Royal Swedish Academy of Sciences in 1785. He was executed in Paris in 1793, during the Reign of Terror, after being accused of being a royalist and counter-revolutionary.