Derived from the Greek onkos meaning “swelling” or “tumour” (refereing to the warty growths found on the lips of all the species in this genus), the Ocidium genus was described by Olaf Swartz in 1800. Odontoglossum was described in 1815 by Humbolt, Bonpland and Knuth from the Greek odonto (tooth) and glossa (tongue) referring to the toothlike projections on the lip.
Brassia was named after Mr. William Brass, a botanical illustrator at that time.