Alte St.-Alexander-Kirche, Romanesque church in Wallenhorst, Germany.

Alte St.-Alexander-Kirche is a Romanesque church east of the Bundesstraße 68 near the Wallenhorst Meyerhof. Excavations in 1968 found 8th-century fieldstone foundations beneath it, and around 800 a 16.35 by 7.10 metre hall church was built partly on them. Around 1000 it became a pillar basilica with two aisles, around 1100 a westwork was added, and a tower followed around 1500.

Excavations in 1968 found 8th-century fieldstone foundations beneath the church, enclosing an area of 23.5 by 12.5 metres. Around 800 a single-nave hall church of 16.35 by 7.10 metres was built partly on them. On 3 January 851 Waltbert, grandson of Widukind, stopped here with the relics of Saint Alexander on the way from Osnabrück to Wildeshausen. Around 1000 the building became a pillared basilica with two aisles, around 1100 the westwork was added, and a tower followed around 1500.

The tower is topped by a gilded hen instead of the usual weathercock; legend says Charlemagne had it placed there so the church would hatch more churches. The parish was a station on the Baltic-Westphalian Way of St James to Santiago de Compostela. Since 1881 the old church has stood without a congregation, its furnishings given to other churches.

The church stands east of the B68 at the Wallenhorster Meyerhof, outside today's centre, which shifted west after the Neue St.-Alexander-Kirche was consecrated in 1881. A car park was laid out next to it for events, and the forecourt was redesigned in 2018. The interior was restored from 1976, with a new floor and heating installed.

The tower is topped by a gilded hen instead of the usual weathercock. Legend says Charlemagne had it placed there as a sign that the church should hatch more churches. The 1968 excavations found 8th-century fieldstone foundations beneath the present building, enclosing an area of 23.5 by 12.5 metres.