Randall’s snapper was first formally described in 1970 as Etelis filamenosus by the French ichthyologist Pierre Fourmanoir with the type locality given as New Caledonia.

[3] In 1977 William D. Anderson Jr, Harry T. Kami and G. David Johnson placed E. filamentosus into the monotypic genus Randallichthys.

The name of the genus honours the American ichthyologist John Ernest Randall who worked at the Bishop Museum, Honolulu, and who made a significant contribution to the study of Indo-Pacific fishes.

[5] Randall's snapper has a relatively elongate body with a short snout, blunt head and a flattened space between the eyes.

The caudal fin is lunate and in yound individuals the rays of the lower lobe may be produced into filaments.