The emergence of the Internet of Things (IOT) has revolutionized connectivity, but it has also introduced with it several vulnerabilities, leaving systems vulnerable to cyber-attacks at various points of entry, from the chip to the cloud. To strengthen Internet of Things security in a comprehensive way, the use of quantum cryptography is paramount. Quantum attacks pose a significant threat to both traditional and lightweight cryptographic systems, compromising their security and necessitating the development of quantum-safe alternatives. In view of the emergence of evolving cyber threats, a comparison analysis among pre-quantum and post-quantum security frameworks for Internet of Things shows that traditional cryptography methods are inadequate. To avoid unauthorized access, we require a specific authentication scheme for the Internet of Things systems. Drawing from NIST Cybersecurity Practice Guides, practical recommendations for implementing post-quantum cryptographic algorithms (PQC) were provided to defend against quantum threats while upholding existing public-key infrastructures’ integrity. PQC options, which include code-based or lattice-based and isogeny-based cryptosystem (SIKE), were deemed most suitable for IoT systems. Quantum Key Distribution (QKD) utilizes elementary particles such as photons to create secure keys that are impossible to break, offering a means to safeguard data. The chapter examines QKD as a fundamental aspect of IoT security, exploring its role in establishing impervious communication channels that are immune to eavesdropping and tampering. The performance of PQCs ranging from resource-constrained IoT Node Layer devices and medium-power devices to powerful cloud servers or Cloudlets is also evaluated. This chapter examines the importance of quantum cryptography, stresses the need for robust authentication systems to tackle emerging cyber threats, and delves into the realm of emerging cyber threats. By embracing quantum-resistant cryptographic techniques, stakeholders can bolster the resilience of IoT infrastructures, safeguarding critical assets and data integrity in an increasingly interconnected digital landscape.