We report a computational study of the mechanism and determination of the rate constants of the Fe + CO₂ → FeO + CO reaction, in the 1000–3000 K temperature range, at the CCSD(T)/CBS//B3LYP/def2-TZVP level of theory. The overall rate constant was obtained by a Kinetic Monte Carlo simulation. The calculated rate constant, at 2000 K, is 9.72 × 10⁻¹³ cm³ molecule⁻¹ s⁻¹, in agreement with experimental measurements: 2.97 × 10⁻¹³ cm³ molecule⁻¹ s⁻¹ [A. Giesen et al., Phys. Chem. Chem. Phys., 2002, 4, 3665] and 1.13 × 10⁻¹³ cm³ molecule⁻¹ s⁻¹ [V. N. Smirnov, Kinet. Catal., 2008, 49, 607]. Our study shows that this reaction follows a complex mechanism, with multiple reaction paths contributing to the overall rate, and that CCSD(T) accurately describes this transition metal reaction.