RLS may refer to:
Education Royal Latin School, a grammar school in Buckingham, England Stevenson School, formerly Robert Louis Stevenson School, California
Science and technology Recursive least squares filter, in minimisation Regularized least squares, for solving least-squares problems Reef Life Survey, a marine monitoring program in Tasmania Restless legs syndrome, a medical disorder
Other uses Real-life slash, a subgenre of real person fiction Rial (disambiguation), plural abbreviation Rls, Middle Eastern currency units Robert Louis Stevenson, Scottish writer