''Aricia saepiolus'', the greenish blue, is a butterfly of the family Lycaenidae. It is found from the northwestern United States to southern Saskatchewan and Alberta.
The wingspan is 21–28 mm. Adults are on wing from June to August.
The larvae feed on ''Trifolium repens'', ''Trifolium hybridum'', ''Trifolium monathum'', ''Trifolium longipes'', and ''Trifolium wormskioldii''.