East Merrimack is a census-designated place (CDP) in the town of Merrimack in Hillsborough County, New Hampshire, United States. There is no village center named "East Merrimack"; rather, the CDP refers to the region of the town of Merrimack lying east of the F. E. Everett Turnpike, overlapping portions of the villages of Reed's Ferry, Thornton's Ferry, and the center of Merrimack.