In this study, GIS-based Multi-Criteria Decision Approach (MCDA) is used to identify suitable locations to use groundwater for irrigation purposes in Salah-Al-Din Governorate, 180 km to the North of Baghdad, capital of Iraq republic. Various criteria are adopted including Electrical Conductivity (EC), Power of Hydrogen (pH), Sodium percentage (Na%), Sodium Adsorption Ratio (SAR), Magnesium Adsorption Ratio (MAR), Kelly's Ratio (KR), climate factor, aquifer thickness, and aquifer elevation. Three datasets are integrated to produce the suitability model, including geophysical data, groundwater wells data and satellite-based climate data. The criteria layers are assessed using the multi-criteria decision approach by combining them together using the weighted overlay function in ArcGIS 10.5. Appropriate weights assigned and integrated into GIS to create the groundwater suitability map for irrigation. Finally, the suitability of the study area for irrigation purposes with its percent to the total area is classified into three classes according to the set criteria used for this purpose: high suitability (35.41%), low suitability (44.22%), and unsuitable/excluded (20.37%). 304 leads to the logical expectation of declination of the Euphrates and Tigris output by 2025 to 50% and 25% respectively [3]. This problem coincides with a significant rise in Iraq's population, increasing water demand, inadequate infrastructure to maintain quality of life and lack of scientific planning for water resources management. Another serious factor in this regard is that the Middle East region (including Iraq) is one of the most vulnerable world regions to the potential impact of climate change (less precipitation, higher transpiration, sea level rise, and drought). According to these facts, the peak water supply in Iraq does not meet the needs, and this problem gets worse with time as the increasing population, the climate change, and unpredictable weather increase water demands largely. The consequences are many, which include a negative impact on agriculture, industry, tourism, and energy sectors resulting in increasing unemployment rates, poverty, food insecurity, and malnutrition.In recent times, there has been a worldwide conviction that groundwater is one of the most important natural water supply resources. When compared with surface water, it has a number of fundamental advantages: it is of higher quality, better protected from possible pollution, less subjected to seasonal and perennial fluctuations, and much more uniformly spread over large regions than surface water. Additionally, groundwater could be available in places where the surface water is scarce. The importance of groundwater as one of the substantial natural resources is accentuated in countries with arid and semiarid climates, where it is widely used for irrigation as in the countries of the Arab region with desert climate [4], these countries started to focus on groundwater resources due to water scarcity and pollution problems [5]. In the times of water scarcity...