Étienne Lenoir (1744–1832) was a French scientific instrument maker and inventor of the repeating circle.
[1] When hired by Jean-Charles de Borda around 1772 to work on the reflecting circle, he was about thirty years old and nearly illiterate.
As a result of this work, he became known as the pre-eminent maker of instruments for astronomy, navigation and surveying in France.
Lenoir was also a member of the Commission temporaire des Arts (1793–1794).
He was made a member of the Bureau des Longitudes in 1814 and received the Legion of Honour.