Sint-Truiden Abbey, Benedictine monastery in Sint-Truiden, Belgium.

Sint-Truiden Abbey is a former Benedictine monastery whose surviving Romanesque west tower rises above a lower brick building with a pointed stone archway. The tower is built of alternating bands of reddish-brown brick and pale grey stone, with vertical stone strips and a small arched window near the top. The abbey church, 100 metres long and 26 metres wide, was demolished in 1798; only the tower and parts of the crypt remain.

Saint Trudo founded the monastery around 655 at Sarchinium, the settlement that became Sint-Truiden. In 883 the Normans laid it waste, and soon after 817 the community adopted the Rule of St. Benedict. Abbot Adelardus II built a Romanesque abbey church 100 metres long in the third quarter of the 11th century; it was demolished in 1798, four years after the abbey's suppression.

The abbey is dedicated to Saint Trudo, who founded the monastery around 655; his grave made it a pilgrimage site, though the dedication to him only became official in the 12th century. The abbey held patronage rights over many parish churches, often dedicated to Saint Clement, who was venerated here. The Baroque gateway of 1665 was built for the abbey's thousand-year anniversary.

The surviving Romanesque west tower and parts of the crypt are what remain of the 11th-century church; the Baroque gateway of 1665 marks the abbey entrance. Parts of the perimeter wall begun around 1520 under Abbot Willem van Brussel still stand. The site lies in the centre of Sint-Truiden, the town that grew around the monastery.

The surviving west tower of the 11th-century abbey church doubled as a donjon in wartime: wooden platforms were built around it from which the abbey's enemies were bombarded, as happened in its conflicts with nearby Brustem. The tower and parts of the crypt are all that remain of a church 100 metres long and 26 metres wide.