The type species Blattoidealestes gracilis was named by South African paleontologist Lieuwe Dirk Boonstra from the Tapinocephalus Assemblage Zone in 1954.

Cuspid teeth are common in Late Permian and Triassic therocephalians, and the closely related cynodonts, which are the ancestors of mammals, but no earlier theriodont possesses this type of tooth.

Due to its small size, Blattoidealestes was originally classified with other tiny therocephalians in a group called Scaloposauria.

Along with many other small-bodied "scaloposaurians", Blattoidealestes was later classified as a member of the advanced therocephalian clade Baurioidea.

[5] A revision of this specimen in 2023 determined that Blattoidealestes instead represents a juvenile scylacosaurid, one of the earliest divering clades of therocephalians.