The Gulf Cooperation Council (GCC) countries are on the verge of a significant shift in waste management, with governments increasingly focused on reforming the waste sector. In Qatar, which currently landfills 90% of its waste, efforts are underway to establish one of the region’s most advanced waste treatment centers, including an anaerobic digestion (AD) facility. However, the question arises whether AD solutions are justified in a fossil fuel-rich nation like Qatar. To this end, this study is among the very few ones that aim to evaluate “concomitantly” the benefits of green energy generation and fertilizer substitution– and the first to consider the specificities of GCC countries. Three organic waste streams were considered: organic fraction of municipal solid waste (OFMSW), livestock manure (LMW) and sewage sludge waste (SSW). The results indicate the potential of AD to generate 850 million m³ of biogas and 2.5 million metric tons of digestate. The biogas could produce up to 3.5 million MWh of surplus energy, equivalent to a reduction of 642 million kg CO 2 -eq. Substituting traditional fertilizers with digestate could further save 49 to 788 million kg CO₂-eq annually– reaching a total of 691-1,430 million kg CO₂-eq mitigated annually. Overall, AD of the three studied organic waste streams can potentially offset 0.7–1.4% of Qatar’s GHG emissions. The findings also highlight the importance of selecting appropriate feedstock sources to maximize GHG savings. For instance, the complementarity between OFMSW and LMW boosts both clean energy production (by OFMSW’s high biogas yield) and fertilizer replacement (by the high LMW nutrient content). 
 
 Graphical Abstract 
 
This paper showed that three of the major organic waste streams in Qatar may be valorized, through AD, to generate two useful products: (1) biogas that can be used for combined generation of electricity and heat, and (2) digestate that can be used as soil amendment and to replace synthetic fertilizers. The outcome is 691-1,430 million kg CO₂-eq mitigated annually.