Excess molar enthalpies, H-E, have been measured for methane with methanol, n-heptane, toluene, and methylcyclohexane at 310.9 and 255.4 K and at 13.8 MPa. Four ternary systems were also studied. These included (methane + (88.2% toluene + 11.8% methanol)), (methane + (93.4% toluene +6.6% methanol)), (methane + (87.8% methylcyclohexane +12.2% methanol)), and (methane + (93.8% methylcyclohexane +6.2% methanol)). The H-E values have been fitted using an ordinary Redlich-Kister equation and a linear least-squares method over the one-phase and the two-phase regions, respectively. A modified Redlich-Kister equation was used to fit H-E values for (methane + n-heptane). The solubility of methane in the liquid phase has been determined from the plot of H-E vs. the mole fraction.