The aqueous electrolyte nonrandom two-liquid (NRTL) model of Chen et al. is extended to represent the excess Gibbs energy of aqueous organic electrolytes. These organic electrolytes exhibit very different solution nonideality from typical aqueous electrolytes with elemental ions. The proposed extension is an integration of the electrolyte NRTL model for aqueous electrolytes and the polymer NRTL model (Chen, 1993) for oligomers and polymers. Organic ions are treated as oligomers that consist of hydrocarbon segments and ionic segments that each exhibit distinctive physical interactions with neighboring species. This integrated NRTL model captures the nonideal phase behavior of aqueous organic electrolytes, including micelle formation. The model further provides a versatile thermodynamic framework to correlate solution nonideality of electrolyte systems, organic or inorganic, and complex systems containing both electrolytes and polymers.