| Olèrdola | |
| Settlement Type: | Municipality |
| Pushpin Map: | Spain Province of Barcelona#Spain |
| Pushpin Map Caption: | Location in Catalonia |
| Coordinates: | 41.3219°N 1.7231°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Spain |
| Subdivision Type1: | Community |
| Subdivision Type2: | Province |
| Subdivision Name2: | Barcelona |
| Subdivision Type3: | Comarca |
| Subdivision Name3: | Alt Penedès |
| Leader Title: | Mayor |
| Leader Name: | Josefina Mascaró (ERC) 2023 |
| Area Footnotes: | [1] |
| Area Total Km2: | 30.2 |
| Elevation M: | 189 |
| Population Density Km2: | auto |
| Population Demonym: | Olerdolenc, olerdolenca Mogenc, mogenca Molantenc, molantenca |
Olèrdola (pronounced as /ca/) is a municipality in the comarca of the Alt Penedès in Catalonia, Spain. It is situated on the northern side of the Garraf massif, and the highest point of the municipality is the Puig de l'Àliga at 468 m.
Olèrdola castle controlled the area of the Penedès Depression in the Early Middle Ages, reaching the height of its significance when its castle dominated the region under the control of the rebellious Mir Geribert, "Prince of Olèrdola". Its importance declined from the twelfth century and its administrative role was taken by Vilafranca del Penedès. The territory has been inhabited since the Neolithic period, and Iberic and Roman remains are juxtaposed with the ruins of the castle. The unusual, circular, Roman chapel of the Sant Sepulcre is near La Plana Rodona.
The name of the municipality is derived from the historical castle, not from any modern settlement. Six villages and twoindustrial zones (polígons industrials) make up the municipality. Populations are given as of 2005:
| Pop 1900: | 1438 |
| Pop 1930: | 1521 |
| Pop 1950: | 1234 |
| Pop 1970: | 1564 |
| Pop 1986: | 1578 |
| Pop Latest: | 3280 |
| Latest Year: | 2007 |