According to the unclonability property of quantum information, it is not possible, in general, to duplicate an unknown quantum state. Quantum cryptography is the science of communication and computation in the presence of an adversary. Because quantum adversaries are also bound by the unclonability property, this creates a myriad of opportunities for quantum cryptographers. We will discuss how unclonability permeates quantum cryptography: from the early findings on quantum money and quantum key distribution, to recent work on unclonable quantum encryption, certified deletion, and unclonable software.