New Hampshire Route 145 (abbreviated NH 145) is a 13.12-mile (21.11 km) long north–south state highway in Coos County in northern New Hampshire. The highway runs between Colebrook and Pittsburg, paralleling U.S. Route 3 for its entire length.
The southern terminus of NH 145 is at U.S. Route 3 in Colebrook on the Vermont border. The highway passes through the towns of Stewartstown and Clarksville. The northern terminus of NH 145 is in Pittsburg at US 3, just after crossing the Connecticut River.