The first catalytic protocol for the regioselective [3 + 2] annulation of N-methyl pyridinium ylides with alkenes to establish various valuable 3-unsubstituted indolizine derivatives is accomplished via palladium catalysis at the unactivated position. The reaction supports a wide range of substrates and shows excellent functional group tolerance, delivering the corresponding annulation products in good to excellent yields. In particular, the gram-scale preparation and valuable diversified derivatization of annulation products further illustrate the potential of this catalytic system. Furthermore, combined computational and experimental studies corroborate the proposed reaction mechanism.