This study proposes an optimal routing model for Software-Defined Networking (SDN) aimed at minimizing network delays. Proper placement of controllers can reduce traffic load, leading to faster data processing and lower data transmission latency. To achieve this, the Whale Optimization Algorithm (WOA) was utilized. The approach leverages information from the controllers about connected switches to enhance network throughput, while also reducing resource usage and improving scalability by minimizing delays. WOA is applied to optimize scheduling and routing within SDN networks, targeting improved energy efficiency among devices based on Wireless Sensor Networks (WSNs). Simulation results demonstrate that the proposed algorithm outperforms other existing methods in terms of key metrics such as authentication key breaking time, network resource consumption, load balancing, delay reduction, and maximum link utilization. Additionally, the algorithm can select the optimal path according to user priorities, providing a comprehensive performance evaluation. Results further indicate that the algorithm performs particularly well in larger network topologies, such as the “Internet Zoo Topology,” and reduces the number of controllers required by strategically placing them in optimal locations.