Célestin Alfred Cogniaux (7 April 1841 – 15 April 1916) was a Belgian botanist.

Amongst other plants, the genus Neocogniauxia of orchids is named after him.

In 1916 his enormous private herbarium was acquired by the National Botanic Garden of Belgium.

With Élie Marchal he edited the exsiccata Les Glumacées de Belgique (1869–1871)[1]

This article about a Belgian botanist is a stub.