Jacques Alexandre Cesar Charles (12 November 1746 - 7 April 1823) was a French chemist who developed the theory of Charles' law around 1787. Charles did not publish his theory; it was published by Joseph Louis Gay-Lussac in 1802.

He was was born at Beaugency , and worked for some years as a clerk in the finance ministry, before pursuing his scientific interests. Charles created the first balloon filled with hydrogen, in 1783, and ascended to a height of around 2 miles.

He was elected to the Académie française in 1785, and later became a professor of physics.