—With the increasing rates of interconnected Internet of Things (IoT) devices within software-defined networking (SDN) environments, Distributed Denial-of-Service (DDoS) attacks have become increasingly common. As a result of this challenge, novel detection and classification methods must be developed based on the unique characteristics of SDN-supported IoT networks. This article proposes a novel approach to detecting and categorizing DDoS attacks that have been optimized specifically for such environments. As part of our methodology, we integrate convolutional neural networks (CNNs) and long-short-term memory (LSTM) models into a multilevel deep neural network architecture. With this hybrid architecture, complex spatial and temporal patterns can be automatically extracted from raw network traffic data to facilitate comprehensive analysis and accurate identification of DDoS attacks. We validate the efficacy and superiority of our proposed approach over traditional machine learning algorithms by conducting rigorous experiments on real-world data sets. Our findings underscore the potential of the multilevel deep neural network approach as a robust and scalable solution for mitigating DDoS attacks in SDN-supported IoT networks. By improving network security and resilience to evolving threats, our methodology contributes to safeguarding critical infrastructures in the era of interconnected IoT ecosystems.