Henri Eugène Lucien Gaëtan Coemans (30 October 1825, Brussels – 8 January 1871, Ghent) was a Belgian Catholic priest and botanist.
In 1848 he obtained his ordination, later serving as a curate in Ghent (from 1853).
In 1864 he became a member of the Académie royale des Sciences et Belles-Lettres de Bruxelles, followed by a professorship at the Catholic University of Leuven in 1866.
[1] As a taxonomist he identified the genus Fittonia (family Acanthaceae).
[3] Coemans issued the exsiccata Cladoniae Belgicae exsiccatae, quas collegit et distribuit, schedulis criticis additis, Eugenius Coemans.