We redescribe Speocyclops yezoensis Ito on the basis of specimens from Japan and from Alaska and Tennessee, U.S.A. The combination of the segmentation of the swimming legs; the lack of dimorphism in the structure of the swimming legs, except for the modified terminal spine of the leg 3 endopodite in the males of some populations; the partly fused proximal segment of leg 5; and, in the female, the peculiar structure of the seminal receptacle provide grounds to propose a new genus Itocyclops to accommodate this taxon. A new record from Tennessee is the first from the eastern U.S.A.