The initials PNB could stand for:
- Peanut butter
- Pacific Northwest Ballet, Seattle, Washington
- Pacific Northwest Bell, a former division of AT&T Corporation and then US West
- Parti National Basque, the Basque National Party
- Parti National Breton, the Breton National Party
- Parti Nationaliste Breton, the Breton Nationalist Party
- Partners for a New Beginning
- Pemodalan Nasional Berhad, in Malaysia
- Peripheral nerve block
- Philippine National Bank in the Philippines
- Police notebook, used by police
- Police Negotiating Board
- Punjab National Bank in India
- Philadelphia National Bank, renamed to CoreStates
- ISO 639 code for Pakistani Punjabi language
- Pottery Neolithic B, a division of the Pottery Neolithic period in archaeology
