The solubility of carbon monoxide in liquid methanol was measured by the decrease in pressure due to absorption at pressures up to 1500 kPa and temperatures up to 140 degrees C. The mole fraction solubility was between 4.2 x 10(-4) and 11 x 10(-3), and the Henry’s law constants were about 250 MPa at temperatures lower than 80 degrees C and pressures up to 1000 kPa. The diffusivity of CO gas in methanol was determined by measuring the diameter and solution time of a single CO bubble in methanol over the temperature range from 25 degrees C to 90 degrees C at a pressure of 500 kPa. The diffusion coefficients ranged between 5 x 10(-9) m(2) . s(-1) and 9.5 x 10(-9) m(2) . s(-1) for the temperature range from 25 degrees C to 90 degrees C and increased as temperature increased. Empirical correlations for the solubility and diffusivity at various temperatures were given.