Poison, as abbreviated in certain computer role-playing games

Packet switched network

Socialist Party of Navarre (Partido Socialista de Navarra, PSN-PSOE)

PlayStation Network, Sony's free online service provided for use with their PlayStation 3 video game console

Project Safe Neighborhoods

Palm Springs (Amtrak station), California, United States; Amtrak station code PSN.

Parson Street railway station, England; National Rail station code PSN.