Wireless communications and networking have experienced explosive growth during the last years so that security issues are a crucial aspect for networks and system design. Thus, the purpose of this Special Section in IEEE Access was to publish innovative and theoretically-grounded research tackling the fundamental and practical challenges of wireless communications and networking security. This Special Section brought together leading researchers and developers from both industry and academia to discuss and present their views on the current trends, challenges, and state-of-the-art solutions addressing various issues related to security in wireless communications and networking. We received a total of 28 submissions, and after a rigorous review process, 13 articles have been selected for publication, which are briefly discussed next.