Siemens & Halske AG (or Siemens-Halske) was a German electrical engineering company that later became part of Siemens.
It was founded on 12 October 1847 as Telegraphen-Bauanstalt von Siemens & Halske by Werner von Siemens and Johann Georg Halske. The company, located in Berlin-Kreuzberg, specialised in manufacturing electrical telegraphs according to Charles Wheatstone's patent of 1837. In 1848, the company constructed one of the first European telegraph lines from Berlin to Frankfurt am Main. Siemens & Halske was not alone in the realm of electrical engineering. In 1887, Emil Rathenau had established Allgemeine Elektrizitäts-Gesellschaft (AEG), which became a long-time rival.
In 1881, Siemens & Halske built the Gross-Lichterfelde Tramway, the world's first electric streetcar line, in the southwestern Lichterfelde suburb of Berlin, followed by the Mödling and Hinterbrühl Tram near Vienna, the first electrical interurban tram in Austria-Hungary. 1882 saw the opening of the experimental "Elektromote" track, an early trolleybus concept in the Berlin suburb of Halensee