Groundwater provides drinking water to approximately one-third of the global population. However, increasing population pressure and contamination from industrial discharge, agricultural runoff, and urbanization are degrading groundwater quality. Therefore, groundwater quality assessment is important for its sustainable management particularly in semiarid regions like southwestern Haryana. However, integrated multidistrict evaluations with hydrogeochemical analysis, fuzzy-based quality indexing, human health risk evaluation, and irrigation suitability mapping remain limited for this region. This study evaluates the groundwater quality across the 11 districts of southwestern Haryana by incorporating multiple analytical techniques like groundwater quality index (GWQI) and fuzzy groundwater quality index (FGWQI), hydrochemical characterization, spatial analysis, human health risk assessment, and irrigation suitability evaluation, highlighting that 15% and 8.8% of the area fall under "unsuitable" category according to GWQI and FGWQI, respectively, reflecting the smoother classification and uncertainty handling capability of the fuzzy-based approach compared to the GWQI method. Spearman's rank correlation analysis reflected a strong association between total hardness (TH), magnesium, chloride, and calcium. This suggests that hardness is influenced by natural mineral dissolution (dolomite, calcite, and gypsum) and anthropogenic inputs (industrial discharge and agricultural runoff). Hydrochemical characterization analysis reflected dominant Ca-HCO and Na-Cl water types (representing recharge-dominated and salinity-affected conditions, respectively), water-rock interaction, evaporation dominance, and underlying sodium-calcium reverse ion-exchange processes. Health risk evaluation highlighted a significant chloride and sodium contamination, and since HI values for both adults and children were above 1, there is a potential noncarcinogenic health risk, but children are more vulnerable as HI value for children is two times higher than adults. The suitability of groundwater for irrigation was tested, which indicated that most of the groundwater samples are suitable for irrigation, though isolated zones with elevated residual sodium carbonate (RSC), magnesium hazard (MH), and percent Na (%Na) may pose sodicity and permeability risks. The findings of this study underscore the need for effective policymaking and an integrated groundwater management framework, including real-time quality monitoring, regulation of industrial wastewater discharge, and precision agricultural practices, and provide a spatially explicit decision-support basis for groundwater quality zoning, risk-based resource allocation, and targeted mitigation planning for sustainable groundwater governance in southwestern Haryana.