The growing global challenge of waste management, particularly in urban settings, necessitates innovative solutions to mitigate environmental pollution, health hazards, and operational inefficiencies in traditional waste collection methods. This paper presents the design and implementation of an IoT-based smart trash bin system aimed at optimizing waste management processes through real-time monitoring of waste levels and the detection of hazardous gases. The system integrates laser diode sensors for waste level detection and gas sensors including TGS2611 and MQ135, for monitoring methane and ammonia emission. These sensors, combined with the ATMEGA128p microcontroller and SIM808 GSM module, allow for seamless data transmission to the Thing Speak cloud platform for analysis and timely decision-making. The system was tested under various conditions, demonstrating high accuracy in fill-level monitoring and gas detection, with response times averaging 5.6 seconds. By providing real-time insights into waste accumulation and environmental conditions, this smart trash bin system offers an efficient, cost effective, and scalable solution for municipalities and waste management authorities. The integration of IoT technology into waste management enhances operational efficiency, reduces environmental hazards, and promotes sustainable urban development. Future work will focus on improving system scalability and minimizing reliance on internet connectivity, making the solution viable for broader applications in both urban and rural settings.