New Hampshire's 12th State Senate district is one of 24 districts in the New Hampshire Senate. It has been represented by Republican Kevin Avard since 2020, following his victory over incumbent Democrat Melanie Levesque.
District 12 covers Nashua's 1st, 2nd, and 5th wards, as well as several towns to its west, including Brookline, Greenville, Hollis, Mason, New Ipswich, and Rindge. It is mostly within Hillsborough County, with a small portion extending into Cheshire County.
The district is entirely located within New Hampshire's 2nd congressional district. It borders the state of Massachusetts.