RTL is an abbreviation used in several contexts.

• Register Transfer Language:
  • (In computer engineering) is a definition of how processor instructions are implemented.
  • (In programming language compilers) is an intermediate representation used in the GNU Compiler Collection.
• Run-time library, in software engineering.
• Register transfer level design/description of digital integrated circuits, in electronic design automation
• "Right-to-left writing " -(Arabic, Hebrew) display on a webpage, and related font issues.
• It stood for a now obsolete circuit design for computer logic gates: resistor-transistor logic.
• It is an abbreviation for Radio Télévision Luxembourg (in French) or Radio Télé Luxemburg (in German), the main brand of the RTL Group.