The present book chapter titled renewable energy sources for sustainable development: an overview gives a comprehensive idea on the crucial role of renewable energy in maintaining global sustainability. It emphasizes on necessity of clean, equitable, and reliable energy solutions against rising energy demand, environment degradation, and climate change. It explains the contribution of renewable energy technologies in achieving major international sustainability objectives including Sustainable Development Goals given by United Nations and Paris Agreement, in terms of enhancing energy security, reduce greenhouse gases, and support complete economic growth. The chapter describes characteristics, applications, and regional relevance of key renewable energy sources such as solar, wind, hydropower, biomass, geothermal, and ocean/tidal energy. It highlights recent technological advancements and innovations in energy storage, efficiency improvement, and smart grid integration in solar and wind technologies that help in accelerating the global energy transition. The chapter also focuses on social and economic benefits of renewable energy sources that promote foster rural development, increase employment opportunities, and contribute to energy equity. It critically evaluates the barriers such as infrastructure gaps, technical limitations, financial constraints, and regulatory challenges which must be addressed to ensure widespread and equitable implementation of sustainable renewable energy. It also gives overview on global and regional initiatives such as international agreements, policy frameworks, education, and role of public engagements for supporting long-term sustainability. The chapter emphasizes strategic planning for successful deployment of renewable energy which requires an integrated approach from policy, technology, financing, and community. This overview serves as a foundational reference for understanding the crucial function of renewable energy for sustainable maintenance of low-carbon and efficient energy generation in the near future.