Casimir Roumeguère (15 August 1828 in Toulouse – 29 February 1892 in Toulouse) was a French botanist and mycologist.
He served as director of the journal Revue mycologique.
His collections of fungi are included in several exsiccatae, including "Fungi Gallici exsiccati", "Fungi exsiccati praecipue Gallici", and "Fungi selecti exsiccati".
His collection of algae is part of the exsicattae series: "Algues de France".In addition to his botanical and mycological research, he published a few works in the fields of geology, conchology and archaeology.