Composting chicken manure (CM) to produce bio-based organic fertilizers or soil improvers offers a circular and sustainable solution, enhancing agricultural versatility while contributing to decarbonization. This study highlights both the benefits and challenges of composting CM and producing a marketable compost. While CM contains valuable macronutrients and organic matter, its low C/N ratio is a drawback for composting. Optimization of composting conditions or co-composting with other biowastes are two potential solutions to overcome this challenge. To address this issue, olive pomace (OP), a byproduct of an industry with significant socio-economic importance in the Mediterranean region, is a potential solution for balancing the C/N ratio and improving compost quality. Furthermore, an industrial approach utilizing vertical cylindrical reactors is proposed to meet EU temperature-time profile requirements in industrial composting. However, further testing and optimization are needed to fully assess the potential of this strategy. Overall, this work lays the foundation for scaling up and validating a bio-circular solution for market introduction, in alignment with EU regulations and the objectives of I3–4-BIOFERTILIZERS project.