The Berlin tramway (German: Straßenbahn Berlin) is the main tram system in Berlin, Germany. It is one of the oldest tram networks in the world having its origins in 1865 and is operated by Berliner Verkehrsbetriebe (BVG), which was founded in 1929. It is notable for being the third-largest tram system in the world, after Melbourne and St. Petersburg. Berlin's tram system is made up of 22 lines that operate across a standard gauge network, with almost 800 stops and measuring almost 190 kilometres (120 mi) in route length and 430 kilometres (270 mi) in line length. Nine of the lines, called Metrotram, operate 24 hours a day and are identified with the letter "M" before their number; the other thirteen lines are regular city tram lines and are identified by just a line number.

Most of the recent network is within the confines of the former East Berlin—tram lines within West Berlin having been replaced by buses during the division of Berlin. However the first extension into West Berlin opened in 1994 on today's M13. In the eastern vicinity of the city there are also three private tram lines that are not part of the main system, whereas to the south-west of Berlin is the Potsdam tram system, with its own network of lines.