Urban composting is a critical practice in sustainable urban waste management, transforming organic waste into valuable compost that enriches soil and supports urban agriculture. This chapter explores urban composting the chemical processes underlying composting and explores the multifaceted benefits it offers to urban environments. The decomposition of organic matter in composting involves a series of complex biochemical reactions facilitated by microorganisms, subsequent in the production of humus, carbon dioxide, in addition to water. Chemical processes include the breakdown of carbohydrates, proteins, and fats, along with nitrogen cycling and the stabilization of organic matter. The chapter also examines the benefits of urban composting, such as reducing landfill waste, lowering greenhouse gas emissions, and enhancing soil health. Additionally, urban composting promotes biodiversity, supports local food production, and contributes to community engagement and education. By understanding the chemical intricacies and broader impacts of composting, this chapter aims to highlight its significance in creating sustainable and resilient urban ecosystems.