Over the last 160 years, a possibly excessive number of species of the tanaidomorphan genus Leptochelia has been described based on its dimorphic males, followed by excessive synonymization to the point of suggesting one cosmopolitan species—called either L. dubia or L. savignyi—for taxa in which the male cheliped is shorter than the body length. It has become apparent over the last 25 years that, in a genus with little dispersive capability, there are numerous, and often sympatric, species of Leptochelia worldwide, none of them cosmopolitan, and distinguished principally on adult female morphology, although that morphology is very conservative. To resolve the resulting confusion over attribution of northeast Atlantic populations to one or other of the earlier-described species, specimens from Madeira, the type locality of L. savignyi, have been analyzed in comparison with material from the western English Channel and northwest Spain. The species is confirmed as Leptochelia savignyi sensu stricto, which is fully redescribed, compared with currently understood sympatric species, and intraspecific and ontogenetic variation is discussed.