Starosedlský Hrádek, Medieval fortified house in Central Bohemian Region, Czech Republic.

Starosedlský Hrádek is a two-storey building with two wings on a low rocky spur above the Zámecký rybník pond northeast of Březnice. The south wing keeps parts of the late Gothic 15th-century structure, and the facades carry psaníčková sgraffito. Ground-floor rooms have ridge and barrel vaults with lunettes, and saddle portals survive.

Staré Sedlo is first documented in 1376, when the village belonged to Petr Lida of Staré Sedlo; a medieval fortress stood here, held in the 15th century by Soběhrd and his son Mikuláš. Jan Zmrzlík of Svojšína seized the fortress in 1472 during a feud with Jan Štěpánovec of Vrtby. In the second half of the 16th century Albert Libštejnský of Kolovrat rebuilt the old fortress as a Renaissance chateau, later altered in Baroque style. From 1663 the Jesuits of Březnice used it as a summer residence until 1773; the Schwarzenbergs bought it in 1868 and held it until 1948.

The village of Staré Sedlo is first documented in 1376, when it belonged to Petr Lida of Staré Sedlo. The castle later passed to the Kolovrat family, and Václav Libštejnský of Kolovrat, who joined the Jesuit order, left the income of the Hrádek estate for ten years to fund the construction of a Jesuit college and church in Prague. From 1773 the estate was administered by a religious fund.

The chateau stands on a low promontory above the Zámecký rybník pond, with the farm courtyard adjoining it; the Chapel of the Holy Trinity lies south of the courtyard in the corner of the garden. The two-storey building has two wings, and parts of the late Gothic structure survive in the southern wing.

The two-storey building has two wings; the southern one keeps parts of a late Gothic structure from the 15th century. Its façades retain psaníčková sgrafita, a diamond-pattern scratched plasterwork. Inside, the ground-floor rooms are vaulted, and one room has four bays of ridge vaulting carried on a central pillar.