Recycling natural fibers plays a crucial role in promoting environmental sustainability by reducing waste, conserving resources, and lowering the environmental impact of textile production. Natural fibers such as cotton, wool, and linen are biodegradable, but when disposed of in landfills, they contribute to pollution and resource depletion. By recycling these materials, we not only extend the life cycle of valuable resources but also decrease the demand for virgin fiber production, which often involves intensive water, energy, and chemical use. Additionally, recycling natural fibers supports a circular economy, encouraging more responsible consumption and production practices while helping to reduce greenhouse gas emissions and textile waste accumulation. On the other hand, the reinforcement of polymer matrices with natural fibers is opening new avenues for enhancing both the environmental and economic sustainability of the polymer industry, while also broadening their applications in engineering. This study investigates the additive manufacturing of composite materials reinforced with short coffee waste shells. A range of characterizations—including scanning electron microscopy and tensile testing—are presented, along with a statistical analysis of the tensile results using Weibull distribution. By incorporating this organic waste into engineered composites, the useful life of coffee shells is extended, contributing to environmental sustainability, and offering potential socio-economic benefits at the local level. The results demonstrate that the produced filaments possess promising mechanical strength and suggest the viability of scaling up the manufacturing process.