| Petra | |
| Settlement Type: | Municipality and town |
| Pushpin Map: | Spain |
| Pushpin Map Caption: | Location in Spain |
| Subdivision Type: | Country |
| Subdivision Name: |  Spain |
| Subdivision Type1: | Autonomous community |
| Subdivision Type2: | Province |
| Subdivision Name2: | Balearic Islands |
| Subdivision Type3: | Island |
| Subdivision Type4: | Comarca |
| Subdivision Name4: | Pla de Mallorca |
| Subdivision Type5: | Judicial district |
| Coordinates: | 39.6137°N 3.113°W |
| Elevation M: | 111 |
| Area Total Km2: | 70.13 |
| Population Demonym: | Petrer, Petrera (Catalan) |
| Population Density Km2: | auto |
| Blank Name Sec1: | Official language(s) |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Postal Code Type: | Postal code |
| Postal Code: | 07520 |
| Area Code Type: | Dialing code |
| Leader Title: | Major |
| Leader Name: | Caterina Mas Bennàssar (2011) |
| Leader Party: | PSM |
Petra (in Catalan; Valencian pronounced as /ˈpe.tɾə/) is a town and municipality on the Mediterranean island of Majorca, in the Spanish autonomous community of the Balearic Islands. "Petra" means "rock" in Latin.
Petra is the birthplace of St. Junípero Serra (1713-1784), a Franciscan friar who founded the first nine of 21 Spanish missions in California from San Diego to San Francisco.