Opo
- OPO is the IATA abbreviation of Porto Airport http://en.wikipedia.org/wiki/Porto_Airport
- Opo is a polite form of "yes" in the Filipino language, usually, used when speaking to one's elders.
- Opo is a common name for the squash species Lagenaria siceraria.
- Opo was the name of a famous dolphin in New Zealand;
- OPO is the abbreviation for Optical parametric oscillator.
- OPO is the abbreviation for Online Political Operative[1].
- OPO is the abbreviation for Online Presence Ontology.