Solubility data of carbon dioxide (CO2) in ionic liquids 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ([BMP][TfO]) and trihexyltetradecylphosphonium bis(trifluoro-methylsulfonyl)imide ([P14,6,6,6][Tf2N]) are presented at pressures up to about 70 MPa and at temperatures between (303.15 and 373.15) K. The solubility of CO2 in ionic liquids was measured by using a high-pressure variable-volume view cell. At high CO2 concentrations in ionic liquids, the equilibrium pressure increased very steeply. The solubility of CO2 in the ionic liquids decreased with increasing temperature. The experimental data for the CO2 + ionic liquid system were correlated using the Peng−Robinson equation of state.