The solubility of methylene blue in methanol, ethanol, 2-propanol, acetone, ethyl acetate, and water was measured at 303.15 K and 0.1 MPa. The solubility of methylene blue in ethyl acetate was very low while the solubility in methanol and 2-propanol was very high and not precisely measurable. In addition, the effect of temperature on the solubility of methylene blue in ethanol, acetone, and water was measured in the temperature range of 278.15 K-318.15 K. The solubility data was modeled with the electrolyte activity model of symmetric e-NRTL. The overall AARD of the model was obtained to be 2.32%. According to the results, there is a good agreement between the experimental solubility data and the solubility estimated with the help of the electrolyte activity model. Furthermore, the solubility data were used to estimate the enthalpy of fusion and melting point of methylene blue, as well as the enthalpy of dissolution and heat capacity for the dissolution of methylene blue in ethanol, acetone, and water.