Othelosoma flavescens, the yellowish flatworm, is a species of land planarian in the family Microplaninae endemic to South Africa.
Othelosoma flavescens generally reaches up to 55 mm long, but when creeping, can reach 80 mm. The dorsal side is a yellow color, and the ventral side is slightly paler. A brown midline on the dorsal side runs from the back end to around 6âÂÂ8 mm from the front. The creeping sole is a whitish color.