Elachista amamii is a moth of the Elachistidae family. It is found in the Ryukyu Islands of Japan and in Taiwan. The length of the forewings is 2.4-3 mm for males and 2.5-3 mm for females. Adults are sexually dimorphic. Male have dark grey-brownish forewing with two indistinct whitish costal spots while females have blackish forewings with four distinct silvery spots. There are multiple generations per year in Taiwan.