Luas [ɫ̪uəsˠ] (Irish for 'speed'), also promoted in the development stage as the Dublin Light Rail System, currently encompasses two unconnected on-street light rail lines in Dublin, Ireland. It is one of 450 light rail systems operating in cities around the world.

Originally under the organization of Córas Iompair Éireann, the project was moved to the Railway Procurement Agency upon that body's inception, while it is operated by Veolia Transport Ireland (formerly known as Connex). The system is also often called a tram network. The Luas is a major part of the Dublin Transportation Office's strategy (2000-2016). It is estimated that around 80,000 people use the Luas daily; and, as of November 2006, over 50 million journeys have been made on the system. The Luas is also one of the safest transport systems in the world.