Mobile Ad Hoc Networks (MANETs) are a self-organizing and adaptive technique comprising several mobile nodes. These networks’ dynamic and changeable architecture creates substantial issues in terms of trust and security for wireless communication lines. To solve these concerns, the Modified Whale Optimization Algorithm (MWOA) is used to provide a secure clustering and routing solution in MANET. The Modified K-means (MKM) method is used in the Cluster Head (CH) selection process to provide effective transmission to the target node without packet loss. MWOA, an optimized technique, is introduced to improve MANET routing security. Key parameters such as energy consumption (EC), packet delivery ratio (PDR), throughput, network Lifetime (NL), and end-to-end delay (EED) are used to evaluate the suggested methodology. Comparative investigation shows that the MWOA methodology outperforms present methods in terms of performance.