Georg Wilhelm Alexander Hans Graf von Arco (30 August 1869 in Großgorschütz – 5 May 1940 in Berlin) was a German physicist, radio pioneer, and one of the joint founders of the "Society for Wireless Telegraphy" which became the Telefunken company.

As a child he was interested in machines of all kinds, but after graduating from the Maria Magdalenen High School in Breslau (now Wrocław, Poland) in 1889, he did not study engineering sciences, but instead attended mathematical and physical lectures at the University of Berlin.

After three years with the military, however, he left to study mechanical engineering and electro-technology at the Technissche Hochschule in Charlottenburg (today Technische Universität Berlin), from 1893.

There he became acquainted with Professor Adolf Slaby, who had participated in Guglielmo Marconi's transmission experiments on the coast of the English Channel.

Building on these attempts, Arco and Slaby in the summer of 1897 used the free-standing bell tower of the Church of the Redeemer, Potsdam, as an antenna, to verify and understand Marconi's experiments.

In the centre of the plaque, which is made from green dolomite, is Atlas with the globe, surrounded by lightning and the text: "At this place in 1897 Professor Adolf Slaby and Count von Arco erected the first German antenna system for wireless communication".

At first Arco was responsible as a laboratory engineer for testing various electrical cable types, but also, through continued contact with Slaby, introduced and developed wireless telegraphy at AEG.

Patent disputes between Siemens and AEG resulted in both companies, at the behest of William II, German Emperor, founding a common enterprise, the Society for Wireless Telegraphy Ltd.

In this regard he surpassed the Löschfunkensender of Max Wien, which had already exhibited a substantially better efficiency than the Knallfunkensender of Ferdinand Braun, and in addition could send on a narrow frequency band.

Arco's greatest service lay in the development of the large radio station at Nauen, 20 miles west of Berlin, thereby helping Telefunken to become a firm of worldwide reputation.