This article provides a sectorial input-output resource assessment and spatial distribution for wastes and residues that could be used as feedstock for bio-SNG production, in the case of the Republic of Ireland (ROI). European and national policies that regulate the use of agricultural and forestry residues, and tertiary waste are reviewed. Geospatial distribution of the available sustainable potential of each feedstock are computed and shown in maps with the existing gas network. Results show that bio-SNG has the potential to provide 10.18 PJ a-1, of which 7.16 PJ a-1 is supplied by dry mixed municipal solid waste, 2.5 PJ a-1 by forestry residues and 0.52 PJ a-1 by sewage sludge, agricultural residues, and digestate. The total amount of potential energy is equivalent to 5.90% of renewable energy supply for heating (RES-H) or 6.62% of RES for transport (RES-T) based on the 2020 energy total final consumption projections in the ROI. Although these results represent the upper sustainable limit of bio-SNG feedstock potential, they represent the first step towards informing gas transmission system operators and policymakers of the decarbonisation potential of bio-SNG. The next stages of this work will optimise the bioSNG supply chain and conduct a full system life cycle assessment.