Estimating the potential land resources suitable for irrigation and water availability is essential for irrigation development and expansion. Ethiopia is very rich in land resources for irrigation but only a small portion of its potential land is being used. This research was conducted at Abbay Basin of Ethiopia to evaluate land suitability for surface irrigation using GIS -based Analytical Hierarchy Process (AHP) techniques and evaluate the surface water potential by considering the most dominant crop that grown in the study area in order to enhance the country's agricultural industry. Some factors that affect irrigation suitability were evaluated and included in this study such as physical land factor (land use, soil, and slope), the factor of market access (proximity to roads and access to market), climate factor (rainfall and evaporation), social factor (population density) and river proximity. And also groundwater depth and salinity were used to assess land suitability using ground water. Necessary input data that was used in this study were collected from governmental organizations and online sources. These factors were weighted using a pair-wise comparison matrix, and then reclassified into different suitability classes by FAO guidelines and other literature and finally overlaid to identify suitable areas for surface irrigation. Surface water data of major river from the Abbay Basin authorities were used to estimate the surface water potential by comparing with the crop water requirement of cereal crops done by CROPWAT8.0 that are mostly grown in the basin. The analysis and the result showed that at 85% threshold level 19192km 2 which is 10% of the study area are suitable for surface irrigation from river water sources and 10364km 2 which is 5.3% of the area are suitable from a groundwater source. The highest potential was obtained on the Tana sub-basin, Dedissa, and plane area of Gojjam from river water, and Jemma, Muger, and Anger sub-basin were suitable from ground water. The slope was the main limiting factor for surface and groundwater source next to river proximity and groundwater depth respectively. From hydrological analysis and the compression between cereal crop water requirement and gauged river showed that 2263 km 2 of land can be irrigated by the rivers in the south Gojjam sub-basin without constructing water storage structure. From this Abbay river covers the highest potential 97% (2198 km 2 ) of land and the other 14 rivers cover only 3% (64.5 km 2 ) of potential land. But there are 10 large irrigation projects in the basin and irrigates large areas by constructing dams on tributary rives and irrigates 308,963 ha of land at full potential. The suitability result is validated using the existing irrigation projects in the study area and almost all (above 88%) areas of irrigation project found within the suitable area from river source and 73% of the well in the study area are found in the suitable area from a groundwater source. Keywords: Abbay basin, Land suitability, surface and groundwater, Analytical Hierarchy Process, Irrigation