Telegrafenberg is a hill in Brandenburg, Germany.
The name derives from an optical telegraph the was built in 1832 on the top of the hill as part of the Prussian semaphore system between Berlin and Koblenz. The optical telegraph line was discontinued with the introduction of the electric telegraph line in 1852.
In 1874 the first observatory was built on the hill. Over the years the site developed in a main center for astronomy, physics and geosciences. A number of institutions have their headquarters on the Telegraphenberg, among them the GFZ German Research Centre for Geosciences, as part of the Albert Einstein Science Park that includes the hill.