Sunscreens can induce ecotoxicological effects and may cause significant impacts in the aquatic ecosystem. In spite of that, ecotoxicological responses of key marine species to sunscreens are scarcely studied in Mediterranean ecosystems, and literature data are lacking. Furthermore, changes in water salinity induced by global warming could significantly affect the ecotoxicological responses of marine species exposed to sunscreens. This research focuses on the evaluation of ecotoxicological responses of Phaeodactylum tricornutum (algae), Corophium orientalis (macroinvertebrate), and Paracentrotus lividus (echinoderms) exposed to sunscreens, which include both chemical- and physical-based. This study, also, analyzes the changes in ecotoxicological responses of the tested species linked to increase in salinity. Results showed that salinity stress significantly increases the toxicity of sunscreens on the tested marine species. Physical-based sunscreens resulted in more toxicity at higher salinity than chemical-based ones toward C. orientalis and P. tricornutum. This study evidenced that risk classifications of sunscreens recorded under standard salinity conditions could be significantly different from that recorded in the natural environment under salinity stress. The collection of a complete dataset on the ecotoxicological effects of sunscreens on marine species tested under salinity stress could be useful to correctly weigh risks for the marine environment under possible future ecological changing scenarios following the global changing driver.