PEN

PEN may refer to:
 * Partido Ecológico Nacional (National Ecological Party), former name of the Brazilian political party Patriota (PATRI)
 * PEN International, a worldwide association of writers
 * English PEN, the founding centre of PEN International
 * PEN America, located in New York City
 * PEN Center USA, part of PEN America
 * PEN Canada, Toronto
 * PEN Hong Kong
 * Sydney PEN, one of three Australian PENs
 * PEN-International, Postsecondary Education Network International, an international partnership of colleges for those with hearing impairment
 * Penang International Airport, Malaysia, IATA airport code: PEN
 * Penarth railway station, Wales, station code: PEN
 * Peruvian sol, ISO 4217 currency code PEN
 * Poder Ejecutivo Nacional, the system of national executive power embodied in the President of Argentina
 * Polyethylene naphthalate, a polyester
 * Private Enterprise Number, an organisation identifier
 * Protective earth neutral in electrical earthing systems