Pfarrkirche Mauer, Catholic parish church in Mauer, Vienna, Austria

Pfarrkirche Mauer is a Gothic parish church in Vienna's Liesing district. Its medieval tower retains a cupola from 1770, while the Gothic choir now serves as a side chapel. The nave was rebuilt from 1934 to 1936 under architect Clemens Holzmeister, who reoriented the church from east-west to north-south.

The church began as St. Erhardt Chapel in the mid-15th century and was fundamentally reshaped during major renovations from 1934 to 1936 under architect Clemens Holzmeister. These alterations defined the appearance that visitors see today.

The church is dedicated to Saint Erhard of Regensburg, chosen because the Eckartsauer family, founders of the building, held their seat at Eckartsau Castle as fiefholders of the Bishopric of Regensburg. The Baroque Pietà by Giovanni Giuliani was donated by Gerhard Weixelberger, abbot of Heiligenkreuz Abbey, whose father was a village judge in Mauer. The high altarpiece showing the Holy Trinity venerated by Saint Erhard is attributed to Franz Zoller, a pupil of Paul Troger.

Visiting is best done during daytime hours when the church is typically open for visitors and the Liesing neighborhood is easily accessible on foot. Keep in mind this is an active place of worship where respectful behavior is expected.

The 1934–1936 rebuild by Clemens Holzmeister removed the whole nave so the church could be reoriented north-south, clearing the east-west alignment that blocked the new tram line. The medieval tower with its 1770 helm and the Gothic choir, now a side chapel, survived the demolition.