Church of Saint John the Baptist, Religious monument in Zaječí, Czech Republic.

The Church of Saint John the Baptist is a single-nave brick church with a polygonal-ended presbytery and a 43-metre tower topped by a pyramidal roof. The presbytery, 12 metres long and 7 metres wide, has stepped buttresses and a ribbed net vault; the nave has a barrel vault with lunettes. A two-arm staircase leads to the rectangular entrance, and a circular clock face sits below the tower's paired windows.

A parish and church are first documented in 1222. In 1508 a late Gothic brick church replaced an earlier wooden one on the site; its fortified presbytery survives, with firing-slit windows in the spiral staircase and sacristy. A nave was added in the 17th century. After a fire destroyed the roof and tower in 1848, the church was rebuilt in 1912–1913 to plans by Vienna architect August Kirstein and reconsecrated on 19 August 1913.

The church is the parish church of the Roman Catholic parish of Zaječí and was entered in the state list of cultural monuments in 1964. Its bells carry Latin inscriptions, among them Sancte Joannes Baptista ora pro nobis on the 0.89 m bell cast by the Brno firm Hiller in 1927.

The building sits in the town center of Zaječí and is easy to reach via the main road, with parking available nearby. The town also offers local restaurants and wine taverns within walking distance.

Behind the altar, during the 1912–1913 rebuild, workers found the entrance to an underground passage; in 2007 the Speleoklub Brno surveyed it and measured 37 m, probably built in the early 16th century. A tombstone of priest Stanislav Reisinger from 1585, found at the same time, is set into the south wall.