The quality of water is usually identified according to its physical, chemical and biological characteristics. The degradation of groundwater quality in a coastal region due to natural processes such as saline water intrusion, wind-driven sea spray and marine aerosols, and interaction of groundwater. This paper aim to perform water quality assessment to determine the effects of saltwater intrusion and groundwater suitability for domestic and agricultural applications. This assessment reports utilizing geographic information system (GIS) and ions geochemistry for appraisal of the groundwater quality around Mallipattinam coastal region, Thanjavur District, Tamil Nadu. There was a meaningful relationship exist among electrical conductivity, chloride, sodium, magnesium and sulphate with total dissolved solids concentrations of groundwater. This study investigates the interaction between groundwater and saltwater from empirical data collected in 15 locations around Mallipattinam coastal region, parameters namely Na+, SO42- and Cl- are responsible for the electrical conductivity (EC) variability in groundwater samples. When comparing our results with potable water quality standards described by various establishments, it had been found that concerning 60% sample water don't seem to be appropriate for consumption purposes. The correlation coefficient for certain variables was performed in this study. EC, Total Dissolved Solids (TDS), chloride had a meaningful relationship amongst themselves and also with Na+, K+ and sulphate. Fluoride and nitrates exist no meaningful correlations with any of the parameters. Chloride also positively correlated with TDS, EC, Na+ and SO42-. Sodium exhibited a positive correlation with K+, Cl- SO(4)(2-)and. The groundwater taken for analysis is categorized as a normal sulfate and chloride type. Hydrochemical groundwater analysis showed that a maximum number of groundwaters belong to the Na+-K+-Cl--SO42- category.y