Henry's law constant data for nitrogen, oxygen, and argon in the ternary liquid mixture water + methanol + ethanol as well as its pure and binary solvent subsystems are reported. The composition and temperature dependence of the Henry's law constant of the air components in these solutions is investigated by Monte Carlo simulation. The underlying molecular force field models are based on the modified Lorentz-Berthelot combining rules that contain one binary interaction parameter, which is mainly taken from preceding work. Predictions from the molecular models for the pure and binary solutions are convincingly compared to experimental literature data, where available. This finding gives confidence that the Henry's law constant for the ternary solution is predicted appropriately. On the basis of an extensive molecular simulation data set, correlations are established for the Henry's law constant between 274.15 and 473.15 K.