OTK

OTK may refer to:


 * Organisations
 * Austrian Tourist Club (German: Österreichische Touristenklub or ÖTK)
 * Obrona Terytorium Kraju (ISO 639:otk), territorial defense forces of Poland
 * Obchodní tiskárny Kolín, Czech paper and card manufacturers
 * One True King, a gaming organization based in Austin, Texas


 * Other meanings
 * Technical Control Department (Russian: Отдел технического контроля or ОТК)
 * Old Turkic (language code)
 * One time key, a method related to encryption
 * Otakuthon, Montreal's anime convention
 * Ottakring, the 16th municipal district of Vienna
 * Over-the-knee boots ("OTK boots")
 * One Turn Kill (Trading Card Game)