The solubilities of benzene and diphenyl in mixed solvents of t-butyl alcohol (TBA) and water at T = (298.15, 303.15, 308.15, and 313.15) K have been determined by spectrophotometry. The mole fractions of TBA in the mixed solvent are x = (0, 0.010, 0.020, 0.030, 0.040, 0.045, 0.050, 0.060, 0.080, and 0.150), respectively. The standard Gibbs energies of solution of benzene and diphenyl have been calculated based on the solubility data. The hydrophobic interaction (HI) for the pair benzene-benzene in the mixed solvent has also been calculated and discussed.