This article reviews the use of molecular dynamics to simulate a wide variety of physical phenomena relevant to droplet vaporization and atomization for both atomic and molecular species. These include both subcritical and supercritical droplet vaporization and mixture effects on the liquid-phase critical point. Droplet formation, collisions, coalescence, and breakup have also been simulated naturally, without any ad-hoc assumptions or the need to track phase boundaries. Finally, all molecular dynamics simulations of liquid flows have reproduced the results given by the solution of the Navier-Stokes equations.