New Hampshire Route 43 is a 16.418-mile-long (26.422 km) north–south state highway in southeastern New Hampshire which runs from Candia to Northwood.

The southern terminus of NH 43 is at an interchange with New Hampshire Route 101 in Candia.

The highway begins on Old Candia Road (which continues west of NH 101 as an unnumbered road) and proceeds north, intersecting with NH 27 before continuing into the town of Deerfield.

To the left is the First New Hampshire Turnpike, which carries US 4, US 202, and NH 9 westbound towards Epsom and Concord.

To the right is US 4 eastbound (which becomes Old Turnpike Road upon crossing into Nottingham just to the east) towards Durham and Portsmouth.