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Ignition delays of lean mixtures of methane–hydrogen with various hydrogen volumetric contents were experimentally studied in a shock tube together with modeling analysis. Results show that the ignition behavior of the methane–hydrogen mixture depending on pressure resembles that of methane for hydrogen fraction less than 40%, with the ignition delays decreasing with increasing pressure. For the hydrogen fraction equal 60%, a negligible promoted effect of pressure on the ignition of the methane–hydrogen mixture is exhibited. For hydrogen fractions equal or greater than 80%, however, the ignition response resembles that of hydrogen in that the ignition delay exhibits a complex dependence on pressure and two-step transition in the global activation energy. Compared with calculated values using four available mechanisms, the NUI Galway mechanism yielded the closest agreement, and was adopted in …