PTK may refer to:

Pairwise Transient Key, a key in the IEEE 802.11i WPA2 specification

Phi Theta Kappa, an international honor society

Phototherapeutic keratectomy, laser eye surgery

Pilotiruemyi Transportny Korabl Novogo Pokoleniya (PTK NP, lit. "New Generation Piloted Transport Ship"), a Roscosmos program to develop a reusable spacecraft

Portal Three Kingdoms, a Magic: The Gathering card set

Post and Telecom of Kosovo

Protein Tyrosine Kinase, an enzyme

PTK Toolkit, a C++ toolkit for creating MacOS and Windows cross-platform games

Oakland County International Airport, a county-owned public-use airport located in Waterford, Michigan with IATA Code PTK.