Methyl methacrylate (MMA) as a specialty monomer of polymers has motivated industry to develop clean and sustainable technologies for its production. Herein, a comprehensive thermodynamic analysis of MMA production from petroleum-based and coal/biomass-based resources is conducted through the Gibbs free energy minimization method. For the petroleum-based route via oxidative esterification of methacrolein (MAL), the production of MMA is sensitive to the composition of methanol (MeOH) and O-2 in the feed, but insensitive to the reaction temperature and pressure. For the coal/biomass-based route via aldol condensation of methyl acetate (MeOAc), a moderate temperature (350-400 degrees C) and large MeOH/MeOAc ratio (>2) give rise to the efficient production of MMA. Hence, significant improvements in the MMA yield could be achieved by optimizing the reaction conditions, which could almost reach the maximal value theoretically of 1.0 mol from per mole of MAL or MeOAc. This study would shed new light on the thermodynamics of MMA production, which is foundational for the development of new processes at the industrial scale.