The poultry industry plays a pivotal role in global food supply, providing consumers with a safe, nutritious, and affordable animal protein. However, intensive poultry production generates large amounts of organic residues, including litter, manure, feathers, carcasses, and slaughterhouse and hatchery by-products, which, if not properly managed, raise significant environmental and public health concerns. Effective waste management strategies are crucial to mitigate these impacts. Composting offers a sustainable solution by transforming poultry residues into a stable, nutrient-rich organic fertilizer through the natural breakdown of organic materials by microorganisms. This process stabilizes nitrogen, improves soil structure, and promotes microbial diversity and nutrient availability, thereby supporting sustainable agricultural practices. The resulting compost can be used to improve soil fertility and reduce reliance on chemical fertilizers. This review focuses on the complex composition of poultry industry residues, their environmental risks, and their potential valorization through composting. It compares different composting techniques, such as traditional composting and vermicomposting, in terms of efficiency in nitrogen stabilization, organic matter decomposition, and compost quality. This chapter also highlights the role of composted poultry residues in regenerative agriculture and agroecological systems, where soil restoration and nutrient cycling are the fundamental principles. By optimizing composting methods, poultry waste can be repurposed as an effective organic amendment, improving soil fertility and reducing pollution risks. Integrating composting into sustainable waste management strategies contributes to climate change mitigation by minimizing nitrogen losses and reducing greenhouse gas (GHG) emissions. These practices not only reduce environmental burdens but also enhance agricultural productivity and sustainability, reinforcing the poultry industry’s role in responsible resource management.