Large-scale and error-tolerant quantum computers will break the currently used tools for enabling confidentiality and integrity on the internet and elsewhere. It has been recognized for the last 10 years that there is an urgent need to develop cryptosystems that can withstand an attacker in the future with a quantum computer. Post-quantum cryptography (PQC), also sometimes known as quantum-resistant cryptography or quantum safe cryptography, means cryptographic algorithms that can run on today’s computers and networks and yet be secure against attackers in the future who have large-scale and error-tolerant quantum computers. This chapter will argue that post-quantum cryptography is more practical and trusted for most real-world systems than quantum key distribution (QKD). The purpose of this chapter is to put cryptography into the broader context of cybersecurity, to briefly explain the threats and risks associated with quantum computing, and to give a nontechnical overview of the post-quantum cryptosystems that are available now.