Santa Maria Assunta, Romanesque collegiate church in Casole d'Elsa, Italy.

Santa Maria Assunta is a Romanesque church in Casole d'Elsa with a Latin cross layout, a central nave, two side aisles, and raised pointed arches throughout the structure. The architectural design creates a clear vertical emphasis that draws the eye upward.

The church is first documented as ecclesia s. Marie in Castello quod dicitur Casule in an act of Guido, bishop of Volterra between 1039 and 1046. A new church was consecrated on 9 November 1161 before the bishops of Pisa, Florence and Volterra. Between the 13th and 14th centuries the Porrina family turned it into a Gothic mausoleum, completed in 1317.

The church became the seat of a college of canons and, from the 13th to 14th century, headed a piviere of 19 suffragan churches. Local lords of the Porrina family turned it into a family mausoleum, installing the tombs of bishop Ranieri del Porrina and of Beltramo Aringhieri, lord of Casole.

The building is accessible to visitors most days, particularly on weekdays outside of religious services. Entry is straightforward, and visitors can explore the interior spaces without special restrictions.

The 1948 restoration, which removed the 1860 travertine facing from the facade, uncovered the bases of the church's columns beneath the floor, along with the old crypt and the foundations of the apses and altars.