Altes Schloss, Town hall and cultural monument in Tettnang, Germany.

Altes Schloss is a town hall and cultural monument in Tettnang, a three-story building with distinctive architectural features. Its prominent entrance portal displays decorated coats of arms representing the original builder and his two wives from noble families.

Count Johann X. von Montfort had the building erected from 1667 on the site in front of the ruined castle, with the Vorarlberg master builder Michael Kuen in charge. After the Thirty Years' War the counts had used the Torchloss as their residence from 1629. The modest size reflected the counts' finances rather than their dynastic claims, so Count Anton III. von Montfort built the Neues Schloss between 1712 and 1728. The Altes Schloss then housed court servants and served as a tithe barn, hop-drying hall and granary until the town bought it in 1903.

The council chamber holds a view of Tettnang painted in 1818, the year the town acquired the building's later role; the picture hangs in the room where the town council meets. The building itself carries the date of its construction on the central gable, beneath the town-hall clock.

The building is Tettnang's town hall, so the historic ground-floor rooms with their barrel vaults and stucco are working municipal offices rather than a museum; visits are best timed around weekday opening hours. The main entrance with the alliance coat of arms faces the square where the St. Georg chapel stands, making the two easy to see together.

In the stairwell hangs a painting dated 1698, brought from the former Capuchin monastery at Langenargen. It shows Saint Anthony interceding for Count Anton III, his wife Maria Anna von Thun and their family, with Lake Constance and Langenargen visible below.