Measurements leading to the calculation of the standard thermodynamic properties for gaseous diphenylsulfide (Chemical Abstract registry number [139-66-2)] are reported. Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, vibrating-tube densitometry, comparative ebulliometry, inclined-piston-gauge manometry, and differential-scanning calorimetry (d.s.c.). Critical properties were estimated for diphenylsulfide. Standard molar entropies, standard molar enthalpies, and standard molar Gibbs free energies of formation were derived for (C6H5)(2)S at selected temperatures T between 298.15 K and 700 K. Densities along the saturation line of dibenzothiophene (CA registry number [132-65-0] are reported for the temperature range 398 < (T/K) < 548. Revised thermodynamic properties for dibenzothiophene based on published results are included.