Burg Gießen, Medieval castle in Kressbronn am Bodensee, Germany.

Burg Gießen is a medieval fortress in Kressbronn am Bodensee featuring an irregular hexagonal defensive wall with round towers. The Gothic residential section with its stepped gables forms the main living quarters of the fortified complex.

The fortress originated before 1250 and underwent major reconstruction between 1482 and 1486 with enhanced fortifications. A moat fed by a canal from the Laimnau river reinforced the defensive capabilities at that time.

The name Gießen refers to the moated castle, whose moat was fed by a canal from Laimnau. The tenor Franz Innozenz Nachbaur was born here on 25 March 1830, the son of the farmer Fidel Nachbaur; he later sang roles in all of Wagner's operas. In 2025, scenes from the ZDF crime film Das fremde Kind were shot at the castle.

The castle is in private ownership and cannot be visited; the grounds and buildings are not open to the public. The site lies north of the Betznau district and east of Gießenbrücke, near the Argen crossing it once guarded. It has been listed as a cultural monument since 29 April 1930.

The tenor Franz Innozenz Nachbaur was born at Burg Gießen on 25 March 1830, the son of the farmer Fidel Nachbaur; he later took the name Franz and sang in all of Wagner's operas. Parts of the 2025 ZDF television film Das fremde Kind from the Der Kommissar und der See series were shot at the castle and on its grounds.