With negligible quantities of nitrogen, wrought and welded solid solution strengthened nickel superalloys usually contain carbides and topologically close-packed phases. However, appreciable nitrogen levels, along with alloy chemistry, can drive the precipitation of a range of unanticipated nitrides in additively manufactured Inconel 625. Metal nitrides (MN), Z-phase (CrNbN), and η-nitrides (M6N) were characterized in Inconel 625 containing relatively low Fe and Ti, and high Si. Conversely, only MN nitrides existed in a similar Inconel 625 alloy with elevated mass fractions of Ti and Fe. These various phases were not fully predicted using state-of-the-art computational thermodynamic tools and databases, indicating a sparsity of data for nickel superalloys. Even after hot isostatic pressing, many nitrides persisted and only experienced slight changes in composition and lattice parameters in both materials. The stability of these nitrides presents a potential pathway for achieving enhanced high temperature and creep properties within this and similar alloy systems.