The solubilities of hydrogen, nitrogen, and carbon monoxide in dodecane were measured using a static equilibrium cell over the temperature range from 344.3 to 410.9 K at pressures to 13.24 MPa. The uncertainty in these measurements is estimated to be less than 0.001 in mole fraction. The data are represented with root-mean-square errors of less than 0.003 mole fraction by the Soave-Redlich-Kwong and Peng-Robinson equations of state when a single empirical interaction parameter, C-ij, is used for each binary system.