New Democratic Party, a social-democratic political party in Canada

National Day Parade in Singapore

National Development Plan in Ireland

Nuclear Disarmament Party, a political party in Australia

Notre Dame Preparatory (Pontiac, Michigan)

Nebraska Democratic Party, a political party in the U.S.A.

Notre Dame Preparatory High School (Scottsdale, Arizona)

National Democratic Party, any one of many political parties of that name around the world

Neighbor Discovery Protocol, an internet protocol

New Democratic Party, any one of several other political parties of that name around the world

Net Domestic Product, an economic quantity