Solubility values of 39 sulfonamides in water, 1-octanol, and 1-hexane were determined by the isothermal saturation method. Thermophysical characteristics of fusion processes (melting points and fusion enthalpies) of the selected substances were measured by the DSC method. The impact of molecule structural modification on solubility processes in the solvents was analyzed. Transfer processes from water to 1-octanol, water to 1-hexane, and 1-hexane to 1-octanol were studied. Correlation equations connecting Gibbs energies of the solubility and the transfer processes with physicochemical descriptors and thermophysical characteristics were obtained.