The exact location of Grimslade is not recorded, but we do know that it lay within the region of Rohan known as Westfold

A township of Rohan, and the home of Grimbold of the Rohirrim. Though its location is never given with certainty, because of its association with Grimbold, we can be sure that it lay in Rohan's Westfold region, the land between Edoras and Helm's Deep. Its name derives from the personal name Grim (presumably Grimslade's founder, and quite possibly an ancestor of Grimbold) and slade, meaning a hillside dell or glade, so we can place Grimslade with some confidence among the foothills of the White Mountains, somewhere to the southeast of Helm's Deep.