Claude Joseph Geoffroy (8 August 1685, Paris – 9 March 1752, Paris) was the brother of Étienne François Geoffroy.
Like his brother, he was an apothecary and chemist.
Having a considerable knowledge of botany, he devoted himself especially to the study of the essential oils in plants.
The son of Matthieu François Geoffroy and Louise Devaux, he was born in Paris on 8 August 1685.
In 1703 he became a master apothecary, and in 1704/05 took scientific excursions throughout southern France.
He then studied botany under Joseph Pitton de Tournefort (1707).
In 1708, following the death of his father, he took charge of the family pharmacy.
In May 1711 he was elected a member of the Académie Royale des Sciences (botany section), subsequently transferring to the "chemistry section" in 1715.
From 1718 to 1720 he was Garde des marchands-apothicaires in Paris, then later served as inspecteur de pharmacie at the Hôtel-Dieu.
In 1731 he attained the title of alderman in Paris.From 1707 to 1751, he published numerous articles in the Histoire et Mémoires de l'Académie royale des sciences.He is known as Geoffroy the Younger to distinguish him from his brother, Geoffroy the Elder (1672–1731).
However, this leads to confusion with his son, Claude François Geoffroy (1729–1753), who is known as "Claude Geoffroy the Younger".