Thirteen vibration-rotation-tunneling (VRT) bands of the CH4—H2O complex have been measured in the range from 18 to 35.5 cm-1 using tunable far infrared laser spectroscopy. The ground state has an average center of mass separation of 3.70 A-ring and a stretching force constant of 1.52 N/m, indicating that this complex is more strongly bound than Ar—H2O. The eigenvalue spectrum has been calculated with a variational procedure using a spherical expansion of a site—site ab initio intermolecular potential energy surface [J. Chem. Phys. 93, 7808 (1991)]. The computed eigenvalues exhibit a similar pattern to the observed spectra but are not in quantitative agreement. These observations suggest that both monomers undergo nearly free internal rotation within the complex