Adolphe Grognier, known under the pseudonym Jean-Baptiste Quélus, (14 January 1813 – 14 December 1883) was a French actor and singer.
The son of lawyer Louis-Furcy Grognier [fr] (1777-1832), and Hélène Caylus, he was appointed twice as director of La Monnaie of Brussels, in 1854 and 1856.
Born in Aurillac, Grognier was first a sailor, then actor.
In 1843 he met the young Rachel in Lyon with whom he fell in love and whose acting troupe he joined for a while.
He was then teacher of singing at the Conservatoire royal de Bruxelles where one of his last pupils was his compatriot Emma Calvé.