Carex chichijimensis is a species of perennial sedge of the genus Carex endemic to Chichijima Island in Japan. C. chichijimensis Katsuy belongs to sect. Graciles Tuck. ex Kük. and is a close relative of C. hattoriana Nakai which is endemic to the Ogasawara Islands. It differs from C. hattoriana in that it has larger, rather glabrous and strongly veined perigynia.