RER may refer to:

Transport

In France

* , or , the commuter rail service serving Paris and its suburbs * , now called , commuter rail service serving

Geneva Geneva ( ; french: Genève ) frp, Genèva ; german: link=no, Genf ; it, Ginevra ; rm, Genevra is the List of cities in Switzerland, second-most populous city in Switzerland (after Zürich) and the most populous city of Romandy, the French-speaki ...

(Switzerland), Annemasse (France) and its suburbs

In Belgium

* ('Brussels Regional Express Network'), the commuter rail service serving Brussels and its suburbs and commuters * ('Ghent Regional Express Network'), the commuter rail service serving Ghent and its suburbs and commuters

In Switzerland

* , the name used for the Bern S-Bahn in French speaking areas. * , commuter rail service serving Vaud and its suburbs * , commuter rail service serving Fribourg and its suburbs * , the name used for the Basel S-Bahn in French speaking areas. * , now called , commuter rail service serving

, Annemasse and its suburbs

In Argentina

* , a planned commuter rail service in

Buenos Aires Buenos Aires ( or ; ), officially the Autonomous City of Buenos Aires ( es, link=no, Ciudad Autónoma de Buenos Aires), is the capital and primate city of Argentina. The city is located on the western shore of the Río de la Plata, on South ...

In Canada

* GO Regional Express Rail, now known as ''GO Expansion'', a planned commuter rail service in Toronto and its suburbs

Other uses

* Rebuilt

Reading electric multiple units The Reading electric multiple units were a fleet of electric multiple units operated by the Reading Company on its Philadelphia commuter rail lines. The majority were constructed by Bethlehem Steel in 1931–1933; American Car and Foundry deliver ...

The Real Estate Roundtable The Real Estate Roundtable is a non-profit public policy organization based in Washington, D.C. that represents the interests of real estate. It focuses on policy areas governing tax, capital and credit, environment and energy, and homeland secur ...

, a non-profit public policy organization that represents the interests of real estate * Real exchange rate, the purchasing power of a currency relative to another at current exchange rates and prices * RēR, the standard abbreviation for the label Recommended Records * '' Resident Evil: Revelations'', a Capcom game * Respiratory exchange ratio, the ratio between the amount of carbon dioxide produced in metabolism and oxygen used * Rough endoplasmic reticulum, a type of endoplasmic reticulum protein-manufacturing ribosomes {{Disambiguation