Petro- is a Greek term for "rock" used as a prefix, for a number of English words, most notably petroleum. For example:
- Petro-superpower - used to describe Russia
- PetroKazakhstan - Canadian oil company
- Petrovietnam - Vietnam Oil and Gas Corporation
- Petro-Canada Centre - two office towers of 32 floors and 53 floor
- Petro-Canada - Canadian oil and gas firm
- Petro-free - Alternative propulsion
- Petro Chemical Complex INA - Indian town
- PetroChina - arm of China National Petroleum Corporation (CNPC)
- Petrobras - Brazilian oil company
- Petro- Also used as a nickname for Andrew
