The red-collared widowbird was described by the French polymath Georges-Louis Leclerc, Comte de Buffon in 1779 in his "Histoire Naturelle des Oiseaux" from a specimen collected in the Cape of Good Hope region of South Africa. The bird was also illustrated in a hand-coloured plate engraved by François-Nicolas Martinet in the "Planches Enluminées D'Histoire Naturelle" which was produced under the supervision of Edme-Louis Daubenton to accompany Buffon's text. Neither the plate caption nor Buffon's description included a scientific name but in 1783 the Dutch naturalist Pieter Boddaert coined the binomial name "Fringilla ardens" in his catalogue of the "Planches Enluminées". The red-collared widowbird is now one of 17 species placed in the genus "Euplectes" that was introduced by the English naturalist William John Swainson in 1829. The genus name combines the Ancient Greek "eu" "fine" or "good" and the New Latin "plectes" "weaver". The specific "ardens" is Latin for "burning" or "glowing".