The Castle of Santa Maria da Feira (Portuguese: Castelo de Santa Maria da Feira) is a medieval castle located in the town of Santa Maria da Feira, in the Aveiro District of Portugal. Situated atop a hill overlooking the town and surrounding countryside, this impressive fortress is one of the most well-preserved and iconic examples of medieval military architecture in Portugal, dating back to the 11th century.

The Castle of Santa Maria da Feira was built during the Moorish occupation of the Iberian Peninsula and played a crucial role in the Reconquista, the Christian reconquest of the Iberian Peninsula from Muslim rule. The castle was originally constructed as a defensive stronghold to protect the town and its inhabitants from invasions and attacks, featuring high walls, fortified towers, and a strategic location that provided a clear vantage point over the surrounding landscape.

Over the centuries, the Castle of Santa Maria da Feira underwent various modifications and expansions, reflecting the evolving architectural styles and military strategies of the time. The castle's design combines elements of Romanesque, Gothic, and Manueline architecture, with its imposing stone walls, battlements, and towers creating a formidable and majestic appearance that dominates the skyline of Santa Maria da Feira.