Charles Joseph Sacleux, CSSp (1856–1943) was a French Catholic missionary and linguist.

[1] He is known also as a botanist, having collected a herbarium of over 2,000 plants in East Africa and Zanzibar.

[1] Sacleux went to Zanzibar in 1879 and was posted to Bagamoyo and began studying Swahili in depth.

[1] In 1890, the botanist Henri Ernest Baillon published Sacleuxia, a genus of flowering plants from Kenya and Tanzania, in the family Apocynaceae and named in Charles Sacleux's honor.

[3] Sacleux wrote: His dictionary of the Comorian language was published in 1979 in two volumes by Mohamed Ahmed Chamanga and Noël Jacques Gueunier.