Next Generation Wireless Sensor Network is a technology that allows various devices to collect data through sensors or sensor networks and share it in an Internet environment. Because most communication is wireless, the network is highly susceptible to various attacks such as blackholes, selective forwarding, and sinkhole attacks, which can compromise the integrity and reliability of the data. Among these, sinkhole attacks are particularly harmful to networks. However, detecting sinkhole attacks in 5G-WSN is more challenging than in ad-hoc networks and wireless sensor networks owing to environmental differences. 5G-WSN have found widespread applications in various fields such as road traffic monitoring, military surveillance, eHealth, mining, manufacturing, and more. These networks play a crucial role in collecting and transmitting critical data, and any compromise in their integrity can have severe consequences, particularly in applications that impact human lives. Therefore, ensuring the security and reliability of these networks is of paramount importance to safeguard the lives and interests of people involved in these applications. This study proposed a Hop Count-Based Detection Scheme for Sinkhole Attack to mitigate the destructive sinkhole attack in the 5G-WSNs. The scheme uses hop counts of the nodes as the bases of detecting the sinkhole nodes in the network. The performance of the proposed scheme was evaluated in terms of probability of false positive, probability of false negative, and probability of detection in contrast to Ibrahim’s Hop Count-Based Detection Algorithm. Moreover, the study evaluated the effects of the packet dropping sinkhole attack with regard to packets loss ratio, packet delivery ratio. On average, from the simulation results, the proposed scheme outperformed Ibrahim’s detection algorithm.