DFT methods are used in calculations of geometries, energies, and frequencies for O (³P) + CH₃OH reactions. CCSD(T) single‐point calculations are carried out followed by extrapolation to the complete basis set (CBS) limit and inclusion of core correlation. The best estimate results of the reaction enthalpies (ΔH) for the first (−7.1 kcal/mol), second (2.0 kcal/mol), and the third (25.8 kcal/mol) reactions path are in excellent agreement with the experimental values, i.e., −7.2 ± 0.2, 1.2 ± 1.0, and 26.0 ± 1.2 kcal/mol, respectively. Rate constants and activation energies in the range of 300–2,000 K calculated with the variational transition state theory are in good agreement with previous studies. H/D and ¹²C/¹³C kinetic isotope effects are also calculated in good agreement with available experimental data. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010