Sticta riparia is a species of foliose lichen in the family Peltigeraceae. Found in Puerto Rico, it was formally described as a new species in 2020 by Joel Mercado‐Díaz and Robert Lücking. The type specimen was collected by the first author in San Cristóbal Canyon at an altitude of 465m (1,526feet); here it was found growing on the vertical surface of a rock by the river. Although most commonly encountered along riverbanks along the Cordillera Central, it has also been found in secondary forests. The specific epithet alludes to its riparian habitat.