Abstract: Two of the most challenging problems at the intersection of electronic structure theory and molecular dynamics simulations are the accurate representation of intermolecular interactions and the development of reducedscaling algorithms applicable to large systems. To some extent, these two problems are antithetical, since the accurate calculation of non-covalent interactions typically requires correlated, post-Hartree-Fock methods whose computational scaling with respect to system size precludes the application of these methods to large systems. I will describe our many-body molecular dynamics (MB-MD) methodology for aqueous systems which overcomes these limitations and enables computer simulations from the gas to the condensed phase, with chemical and spectroscopic accuracy. MB-MD is a unified molecular dynamics framework that combines many-body representations for potential energy, dipole moment, and polarizability surfaces derived entirely from correlated electronic structure data-driven approaches, with quantum dynamics methods that explicitly account for nuclear quantum effects. I will discuss the accuracy and predictive ability of the MB-MD methodology in the context of molecular modeling of complex aqueous systems, from gas-phase clusters to bulk solutions and interfaces, with a particular focus on the relationships between structural and dynamical properties and vibrational spectra.