Oldenlandiopsis callitrichoides (Griseb.) Terrell & W. H. Lewis (Rubiaceae) was found naturalized in the lowlands of northern and southern Taiwan. This represents a new record not only for this species but also for the genus on this island. A taxonomic account of O. callitrichoides is treated in this study. A line-drawing, photographs and distribution map of this species are also provided to aid in identification.