A manganese-mediated dehydrogenative direct alkylation of 2-pyridones with diethyl malonates has been developed. A similar reaction system is applicable to the direct arylation with arylboronic acids. These manganese-based reactions occur regioselectively at the C3 position of the 2-pyridones. The observed high C3 regioselectivity can complement precedented C-H functionalization protocols of the 2-pyridones in view of the site selectivity.