Alexandre Léon Étard (1852–1910) was a French chemist.

He was born on 5 January 1852 in Alençon,[1] and died on 1 May 1910 in Paris.

[2][3] Étard was a preparer at the Wurtz Laboratory at École Pratique des Hautes Études, and became a member of the Société de Chimie Industrielle in 1875.

He studied at the Sorbonne, and earned a Doctorate in Physical Sciences in 1880.

[1] Étard discovered the oxidation reaction of methyl groups linked to aromatic rings or to heterocycles using chromyl chloride, known as the Étard reaction.