<p>In recent times, valorized agro-waste has found cogent suitability and applications as value-added material for green sustainability and, circular economy, and sustainability. Hence, this review is an overview, in-depth and comprehensive evaluation of the potential of biochar within the context of water and wastewater treatment, energy, soil remediation and enhancement, construction industry, waste management, green chemistry, circular economy, etc., geared towards achieving the full prospect of the sustainable development goals. Valorized agro-waste used for biochar syntheses properly aligns with circular economy principles by its conversion to a resourceful value-added material. This concept establishes the principles of sustainable waste management, thereby drastically resulting in a decrease in negative environmental impacts, conservation of benign ecosystem, conservation of natural resources and the enhancement of sustainable management. This promotes sustainable environmental re-engineering for improved resource recovery, advancement of green and circular economy, environmental optimization and management for viable productivity in all spheres of human endeavors.</p>