As an acronym, BLS may stand for:
BLS AG is a Swiss railway company created by the 2006 merger of BLS Lötschbergbahn and Regionalverkehr Mittelland AG.
Synchronous Optical Networking (SONET) and Synchronous Digital Hierarchy (SDH) are standardized protocols that transfer multiple digital bit streams synchronously over optical fiber using lasers or highly coherent light from light-emitting diodes (LEDs).
The Boston Latin School is a public "exam school" in Boston, Massachusetts. Established on April 23, 1635, it is arguably either the oldest or second oldest school as well as the first public school in the United States.
The BLS RABe 525, also known as NINA or Nina, is a Swiss electric multiple unit built by Bombardier Transportation with electrical equipment by Alstom.
The Bureau of Labor Statistics (BLS) is a unit of the United States Department of Labor. It is the principal fact-finding agency for the U.S.
The Bern–Lötschberg–Simplon railway (BLS), known between 1997 and 2006 as the BLS Lötschbergbahn, was a Swiss railway company.
The Black Screen of Death (BkSoD) is an error screen displayed by some operating systems after encountering a critical system error which can cause the system to shut down.
The BLS International School is a school in Uttar Pradesh, India.
The Re 460 (popularly known as the Lok 2000) series are modern four-axle electric locomotives of the Swiss Federal Railways.