U5 is a line on the Berlin U-Bahn. It runs from Hauptbahnhof in Mitte eastwards through Alexanderplatz, Friedrichshain, Lichtenberg and Friedrichsfelde, surfaces in Biesdorf-Süd to pass Kaulsdorf and Hellersdorf above ground and finally reaches city limits at Hönow.

The Berlin U-Bahn is a rapid transit system in Berlin, the capital and largest city of Germany, and a major part of the city's public transport system. Together with the S-Bahn, a network of suburban train lines, and a tram network that operates mostly in the eastern parts of the city, it serves as the main means of transport in the capital.