PTN
PTN may refer to:
 Harry P. Williams Memorial Airport (IATA/FAA code PTN)
 Paramount Television Network (1948–1956), U.S.
 Partido Trabalhista Nacional (National Labour Party) - a mid-ranking party of the Fourth Brazilian Republic, best known as the party of Jânio Quadros from 1954 to 1965
 Partido Trabalhista Nacional (National Labor Party), former name of Podemos (Brazil)
 Pleiotrophin, a protein