S. fragilis may refer to:
Salinator fragilis, an air-breathing land snail species Salix euxina, a non-hybrid species Salix × fragilis, the hybrid between Salix euxina and Salix alba Sinocoelurus fragilis, a theropod dinosaur species from the Upper Jurassic Skania fragilis, a fossil arthropod species from the Cambrian Swainsona fragilis, a flowering plant species in the genus Swainsona native to Australasia
See also Fragilis (disambiguation)