The tanaidid genus Sinelobus was long considered to be monotypic, comprising a cosmopolitan species, S. stanfordi, predominantly associated with restricted, largely hypohaline waters. Recent discoveries of distinct species of Sinelobus in Australia have prompted closer examination of material from localities remote from the Central American Pacific coast (the type-locality of S. stanfordi).Re-examination of material from the Netherlands (north-east Atlantic) and from Hong Kong (South China Sea) has resulted in the distinction of two new species, which are described herein. Problems with the familial nomenclature of this taxon have been identified, and the family name is corrected to Tanaididae.