The solubility of oxygen in 21 pure organic solvents was measured at 298.2 K and 101.33 kPa using the static method. The Hansen solubility parameters (HSPs) of oxygen were determined from the measured solubilities in the pure solvents. The HSPs of oxygen were δd = 6.7 MPa1/2, δp = 0.0 MPa1/2, and δh = 3.8 MPa1/2, where d, p, and h stand for dispersion forces, dipole interaction, and hydrogen bonding, respectively. A linear relationship between the log of the gas solubility (log x G) in pure solvents and the difference between the HSP values of oxygen and the pure solvents was obtained with a high correlation coefficient of 0.944. In addition, the solubilities of oxygen in mixed solvents were measured, and these were compared with the oxygen gas solubility calculated from the HSPs of oxygen.