The solubility of carbonyl sulfide (COS) in two low vapor pressure organic solvents, namely, sulfolane (SFL) and gamma-butyrolactone (GBL), was measured by experimental trial. The gas solubility was determined by using an isochoric saturation method under a static situation at temperatures from 303.15 to 353.15 K and pressures from the vapor pressure of solvent up to about 1.2 MPa. The absorption data were correlated by using the Peng-Robinson-Stryjek-Vera (PRSV) cubic equation of state (EoS) as the phi-phi approach and the Krichevsky-Ilinskaya (KI) model with a combination of the PRSV EoS as the gamma-phi approach. Using the solubility data, Henrys law constant, Gibbs free energy, enthalpy, entropy, and gas molar volume at infinitely diluted solutions were calculated and interpreted.