PTN may refer to:

• A public university (perguruan tinggi negeri) in Indonesia
• 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