Uherský Ostroh Castle, Medieval castle in Uherský Ostroh, Czech Republic.

Uherský Ostroh Castle is a castle in Uherský Ostroh, Czech Republic, created by rebuilding a medieval castle. Its rectangular core measures 48 by 44 metres, and a square residential tower 12 by 11.5 metres survives in the masonry. The courtyard is flanked by arcaded galleries, with rusticated pillars on the ground floor and Tuscan columns above.

The castle was probably founded by the ruler after 1260; the first written mention dates from 1286, when it was called Stenice and a burgrave Matouš of Černá Hora was named. In 1318 Olomouc bishop Konrád I received it in pledge, and two years later the Šternberk family held it. Margrave Jan Jindřich acquired it in the mid-14th century and made building alterations; the Kunovice lords began converting the Gothic castle into a Renaissance château after 1516, with major work after 1566 under Jetřich of Kunovice.

The name Ostroh refers to the island setting: until the early 20th century the castle and town stood on land encircled by arms of the Morava River. The former farm buildings now house a workshop of the company Lidové tradice a řemesla making folk costumes, and the town information centre.

The castle stands at the town center at Zámecká 24 where the town hall and visitor information office are now located. The central position makes it easy to find and visit while exploring the town.

The castle core measured 48 by 44 metres, and a square residential tower of 12 by 11.5 metres survives inside the later walls. In the cellars and ground floor, the longitudinal walls of the 13th-century palace and part of the north-east and north-west perimeter wall are still visible. A fragment of a vault rib in the tower dates from the building work of Margrave Jan Jindřich.