| Heiligenkreuz Abbey | |
|---|---|
 Aerial view of Heiligenkreuz Abbey | |
| Religion | |
| Affiliation | Roman Catholic Church |
| Ecclesiastical or organizational status | Abbey |
| Leadership | Maximilian Heim |
| Year consecrated | Abbey Church (1187) Monastery complex (1240) |
| Status | Active |
| Relics | True Cross, Crown of thorns, Otto of Freising |
| Location | |
| Location | Heiligenkreuz, Lower Austria |
  Shown within Austria  Heiligenkreuz Abbey (Lower Austria) | |
| Geographic coordinates | 48°03′18″N 16°07′52″E / 48.05510°N 16.13122°E |
| Architecture | |
| Architect(s) | Giovanni Giuliani |
| Type | Abbey |
| Style | Cistercian, Gothic, Romanesque |
| Founder | Leopold III, Margrave of Austria |
| Groundbreaking | 11 September 1133 |
| Website | |
| www | |
Heiligenkreuz Abbey (German: Stift Heiligenkreuz; English: Abbey of the Holy Cross) is a Cistercian monastery in the village of Heiligenkreuz in the southern part of the Vienna woods, c. 13 km north-west of Baden in Lower Austria. It is the oldest continuously occupied Cistercian monastery in the world.