New Hampshire Route 11 is a 108.223-mile-long (174.168 km) east–west state highway in New Hampshire, running completely across the central part of the state. Its western terminus is at the Vermont state line in Charlestown, where it continues west as Vermont Route 11. The eastern terminus is at the Maine state line in Rochester, where it crosses the border with U.S. Route 202 and continues as Maine State Route 11.
Its number is derived from its original 1925 designation as New England Interstate Route 11.
The highway follows a generally southwest to northeast alignment from the Vermont state line until reaching Lake Winnipesaukee, then turns southeast for the remainder of its routing to the Maine state line.
NH 11 begins on the western bank of the Connecticut River, where VT 11 crosses from Springfield, Vermont, into Charlestown, New Hampshire, just feet from its intersection with US 5. Just north of the town center, the highway meets and joins NH 12 north towards Claremont. NH 11 and NH 12 are cosigned for 9.9 miles (15.9 km). NH 12A, a western bypass of downtown Claremont, splits off just south of the city line. In downtown Claremont NH 11 leaves NH 12 and NH 103 joins eastbound, starting a longer 13.0-mile (20.9 km) concurrency. The two highways cross the Sugar River and meet the southern terminus of NH 120 before continuing east towards Newport. In downtown Newport, NH 11 and 103 briefly join NH 10 before turning east again to leave town. The two routes continue east for another 3.2 miles (5.1 km) before NH 103 splits off to the southeast.
NH 11 continues east into Sunapee until reaching the town center, where it meets NH 103B, a connector to the Mount Sunapee Resort. NH 11 turns northward along the western side of Lake Sunapee and rounds the northern end of the lake at Georges Mills, turning back to the east. NH 11 enters the town of New London, meets the northern terminus of NH 103A (which runs along the east side of the lake) and immediately turns onto Interstate 89 south (at exit 12). NH 11 runs along I-89 for 3.0 miles (4.8 km) before departing at exit 11. After leaving I-89, NH 11 continues east, crossing NH 114 before entering the town of Wilmot. Continuing east into Andover, the highway meets the southern terminus of NH 4A then joins US 4 for 2.7 miles (4.3 km). NH 11 then splits off, continuing northeast into Franklin. The road meets NH 3A near the west bank of the Pemigewasset River, and NH 11 turns south along NH 3A into downtown Franklin.