The drivers of low-frequency (i.e., interannual-to-multidecadal) variability and change in ocean heat content (OHC) on the U.S. Northeast Shelf (USNES) are investigated through heat budget analysis and Regional Ocean Modeling System experiments. Over the entire USNES, the drivers of low-frequency OHC variability are surface heat flux, horizontal advection, and horizontal mixing. Surface heat flux in the U.S. East Coast region has been responsible for warming since 1977, and it dominates the interannual-to-decadal OHC variability in the shallow shelf area near the coast. In contrast, remote forcing from the open Atlantic has a weak impact on the warming trend due to contrasting effects from the northern and eastern parts of the Atlantic. Still, it plays a more significant role in interannual-to-decadal OHC variability in deep shelf near the continental break. Furthermore, both regional and remote forcings are important for the interannual-to-decadal variability of OHC integrated over the entire USNES. Regionally and remotely forced sea surface temperature anomalies alter surface heat flux over the USNES, inducing OHC variability. The remotely forced OHC anomalies result primarily from the advection of remotely forced temperature anomalies from the Scotian Shelf and along the shelf break by the currents driven by both regional and remote forcings. Furthermore, current along the Scotian shelf significantly contributes to OHC advection across the northern boundary of the USNES. In contrast, the influence of the Gulf Stream on OHC advection across the southern and eastern boundaries of the USNES is relatively moderate.