DPO
- D.P.O. (The X-Files)
- Data protection officer
- Days payables outstanding
- Dayton Philharmonic Orchestra
- Democratic Party of Oregon
- Detrended price oscillator
- Devonport Airport
- Digital Policy Office
- Direct preference optimization
- Direct public offering
- Discontinued post office
- Double pushout graph rewriting
- Dublin Philharmonic Orchestra
- Hong Kong
- List of diplomatic missions of the United States
- Order of Pius IX
- Oscilloscope
- United Nations Department of Peace Operations