The exponential growth of the Internet of Things (IoT) ecosystem has revolutionized critical sectors, including healthcare, manufacturing, and smart cities, while simultaneously introducing complex security challenges. Traditional cryptographic primitives, including Rivest-Shamir-Adleman (RSA) and Elliptic Curve Cryptography (ECC), are vulnerable to quantum computational attacks, particularly Shor’s and Grover’s algorithms. This chapter presents a comprehensive exploration of Post-Quantum Cryptography (PQC) and its integration within resource-constrained IoT environments. It systematically examines major PQC families’ lattice-based, code-based, multivariate, hash-based, and isogeny-based cryptography, assessing their operational feasibility, implementation overhead, and quantum resilience in IoT scenarios. The research introduces quantum-cooperative communication architectures for two-node, three-node, and generalized N-node configurations, incorporating partial and full cooperation models managed by centralized quantum-enabled servers. A comparative performance analysis of standardized PQC schemes, including CRYSTALS-Kyber, Dilithium, SPHINCS+, and BIKE, reveals trade-offs among key parameters such as size, computational latency, and energy consumption. Findings indicate that lattice-based schemes achieve an optimal balance between performance and security for IoT devices, while hash-based approaches require higher resource allocation despite strong security guarantees. The chapter concludes with standardization recommendations and deployment strategies for quantum-resilient IoT infrastructures aligned with the National Institute of Standards and Technology (NIST) post-quantum cryptographic guidelines.