<p>Vibrational strong coupling (VSC) can steer chemical reactivity and energy transfer by hybridizing molecular vibrations with cavity photons. However, it remains unclear how coupling a macroscopic ensemble of molecules to an infrared (IR) cavity alters local molecular dynamics, particularly in the absence of external IR pumping. Herein, a collective and remote energy transfer pathway from molecular electronic to vibrational transitions is identified under VSC conditions using the Pauli–Fierz light-matter Hamiltonian. Following sudden electronic transitions, real IR photons are produced due to rapid change of permanent dipoles, akin to the dynamical Casimir effect; vibrational polaritons then coherently funnel the photonic excitation to molecular vibrations before any dissipation occurs. Analytical solutions and numerical simulations reveal that the rate of this electronic-to-vibrational energy transfer depends quadratically on the number of molecules and is resonantly enhanced by VSC. During this “supervibronic” transition process, the vibrational energy gain per molecule can remain meaningful in the macroscopic limit, suggesting experimentally accessible signatures using conventional VSC devices.</p><p></p>