Pokrzywno Castle, Medieval castle ruin in Pokrzywno, Poland.

Pokrzywno Castle is a ruined Gothic Teutonic Knights' commandery on an irregular plan, consisting of an upper ward and two outer baileys. The best-preserved elements are the gatehouse of the upper ward, a converted granary, the gate of the inner bailey, and fragments of the main building and defensive walls. A two-bay gate chapel once stood above the entrance.

The Teutonic Knights took over an older fortification here in 1231 and began building the stone castle in the 1250s; the first recorded commander, Heinrich Brabantius, is documented in 1278. The castle remained a commandery seat until the death of the last commander, Friedrich von Zollern, and in 1454 it fell to the Prussian Confederation. From 1566 it was a Polish starost's residence, was damaged during the Swedish occupation of 1657, and after 1784 was demolished and abandoned.

The chapel of the castle was a two-bay gate chapel above the entrance, a feature rare among Teutonic Order castles. It was profaned by Swedish troops during the siege, and its weakened vault collapsed in 1789, after which the ruins were further dismantled.

The ruins sit on a hilltop and require some care when walking, as surfaces are uneven and parts of the site are loose. There are no visitor facilities on-site, so it helps to arrive prepared with information about the layout.

The upper castle's gatehouse preserves a two-bay chapel above the entrance passage, a rare feature in Teutonic Order castles. The inner bailey also retains a 37-metre-long granary and a decorated gate on its eastern approach.