The origin of the rapid neutron capture process (r-process) elements remains the biggest unsolved question in our understanding of the origin of the elements in the Milky Way. The r-process is responsible for producing around half of the elements heavier than iron, but the astrophysical site in which it occurs is still uncertain. The most likely sites for the formation of these nuclei involve dynamical events in the lives of neutron stars: the inner most regions of massive stars during core collapse supernovae and the merger of a neutron star and another compact object. In both of these environments, neutrinos, nuclear physics, and gravity play paramount roles in determining the evolution of the dense object itself and in determining what nuclei are synthesized in material that is ejected from the system. I will first discuss prospects for the r-process in the inner most regions core-collapse supernovae. This part of the talk will focus on my work studying neutrino emission during core-collapse supernovae, which has constrained the possible modes of nucleosynthesis in these events. Second, I will discuss nucleosynthesis in material ejected during binary neutron star mergers and my work predicting optical transients powered by the decay of ejected radioactive nuclei. I will highlight some of the uncertainties that exist in both of these scenarios, and how these uncertainties can be reduced with future theoretical and computational work with input from current and next generation observational and experimental facilities.