Théodore Lacordaire or Jean Théodore Lacordaire (1 February 1801 – 18 July 1870) was a Belgian entomologist of French extraction. In spite of his obvious interest in natural history, his family sent him to Le Havre to study "le droit", or the law. In 1824, he embarked for Buenos Aires where he became a commercial salesman. He traveled widely in South America using every opportunity to carry out many observations on local fauna. Lacordaire was elected to the American Philosophical Society in 1856. In 1868, he was elected a foreign member of the Royal Swedish Academy of Sciences.