Glacial Isostatic Adjustment (GIA), or postglacial rebound refers to the crustal response to glacial loading and unloading processes. In this investigation, we run numerical simulations using different rheological parameters and ice loading histories to obtain models of the glacial isostatic response for the Grand Banks of Newfoundland. The objective is to assess in general the potential impact of GIA on hydrocarbon reservoirs and trapping structures in terms of tilting, deformation, fault activity or geochemical implications on the trapped fluids. Comparisons may be drawn to related studies, including analogous impacts on reservoirs in the Barents Sea, as well as validation of GIA model predictions of vertical crustal motion using GNSS stations, levelling networks and relative sea level (RSL) observations at numerous sites across eastern Canada. By running a series of GIA models, a range of vertical motion rates are output through time to determine displacement amounts, and calculations are performed on these outputs to disseminate other valuable data attributes such as the displacement gradient and differences in time and space. In general, the vertical motion rate is seen to change drastically over time for certain points, as the lag in response of regions near the ice periphery leads to a distinct pattern of uplift and subsidence. The Grand Banks generally experienced between 57 m of subsidence to 34 m of uplift since the last glacial maximum, depending on the specific location and the GIA model parameters. At the reservoir scale, model results along a 10 km baseline show up to −1.0–1.5 m of differential vertical displacement, which could have led to reservoir tilting or even hydrocarbon migration. As a result of this study, it is clear that there are implications of GIA on hydrocarbon reservoirs since the Last Glacial Maximum, and these effects are ongoing.