Elachista planicara is a moth in the Elachistidae family. It was described by Kaila in 1998. It is found in Japan (Hokkaidô, Honsyû, Sikoku, Kyûsyû) and the Russian Far East (Kuriles). The length of the forewings is 4–5.2 mm for males and 4–5 mm for females. Adults are similar to Elachista sasae, but are more slender-winged and lighter in colour. Adults have been recorded on wing in early July.