The study aimed at the determination of the influence of organic load, simulated by the dissolution of appropriate humic acid (HA) concentrations in water, on the defluoridation efficiency of nano magnesium oxide (NMgO), a nascent reactive material for groundwater (GW) defluoridation. The kinetic analysis of the process of sorption of HA and fluoride (F-) by the NMgO showed that the rate of sorbate removal is a function of the sorption capacity of the sorbent and not the solution concentrations of the sorbate. The Frumkin isotherm equation gave the best description of HA sorption while Freundlich isotherm equation gave a better description of the F sorption. The determination of the efficiency of interfering ions on the removal of HA and F-, from both synthetic feed water and natural GW systems, showed that the removal of HA was not affected, when F was the interfering ionic specie, but the negative impact of the presence of HA, as the interfering ion, on the defluoridation efficiency of the NMgO was felt only at the initial F- concentration that is <5 mg/L. The determination of the effects of simultaneous removal of F- and HA on the quality characteristics of the treated GW showed that significant reduction in the ionic activities and the concentrations of the total inorganic carbon and carbonate of the treated GW samples were observed.