Northfield sits along the Winnipesaukee River in Merrimack County, directly adjacent to Tilton and sharing much of its commercial and cultural life with its neighbor. The town's mill-era buildings along the river reflect a shared industrial history with the surrounding area.

Northfield's rural hills contrast with the busier commercial strip in neighboring Tilton, giving residents both quiet residential neighborhoods and easy access to shopping and dining just across the town line. The Winnipesaukee River offers fishing and paddling opportunities.

Housing in Northfield tends to be more affordable than in the Lakes Region towns further north, drawing families and value-seekers who want proximity to Tilton's amenities without paying a Lakes Region premium. The town's rural character remains intact away from the river corridor.