Heiligenkreuz (Central Bavarian: Heilingkreiz) is a municipality in the district of Baden, in the Austrian state of Lower Austria.

Heiligenkreuz is a stop on the old Via Sacra from Vienna to the pilgrimage site Mariazell in Styria.

In 1133 the Babenberg margrave Leopold III established the Heiligenkreuz monastery in the sparsely settled area.

Over the centuries, a small settlement grew outside the monastery walls, which was incorporated as the present-day municipality in 1849.

The largest relic of the Holy Cross north of the Alps is located in the town at the monastery.