PDB may refer to:
- Protein Data Bank
- Potato Dextrose Broth, see Potato dextrose agar
- Chess Problem Database Server (PDB Server)
- Partei der deutschsprachigen Belgier, the Party of German-speaking Belgians
- President's Daily Brief
- Promised Day Brigades
- 1,4-Dichlorobenzene (paradichlorobenzene)
- Pee Dee Belemnite - a standard for stable Carbon-13 and Oxygen-18 isotopes.
- Power Distribution Board (electricity)
- The Python debugger.
.pdb is a file type used:
- as an envelope for Palm OS databases. See PDB (Palm OS)
- as a program database, containing symbols used in debugging native Windows code
- as an e-book format for certain e-books, although it is not strictly a file type format unto itself
- Protein Data Bank (file format)