New Hampshire state elections in 2018 were held on Tuesday, November 6, 2018, with the primary elections being held on June 5, 2018. Voters elected two members to theUnited States House of Representatives, the governor of New Hampshire, all five members to the Executive Council, all 24 members to theNew Hampshire Senate, and all 400 members to theNew Hampshire House of Representatives, and other local elected offices.

The primary election was held on Tuesday, June 5, 2018.Turnout by county:
| County | Registered voters[1] | Ballots cast[2] | Turnout (%) |
|---|---|---|---|
| Belknap County | 46,189 | 11,352 | 24.58% |
| Carroll County | 37,233 | 11,274 | 30.28% |
| Cheshire County | 57,022 | 12,641 | 22.17% |
| Coos County | 20,094 | 4,599 | 22.89% |
| Grafton County | 67,404 | 14,536 | 21.56% |
| Hillsborough County | 270,722 | 63,357 | 23.40% |
| Merrimack County | 109,163 | 28,302 | 25.93% |
| Rockingham County | 234,112 | 54,722 | 23.37% |
| Strafford County | 92,087 | 20,965 | 22.77% |
| Sullivan County | 28,370 | 6,514 | 22.96% |
| Totals | 962,396 | 228,262 | 23.72% |

The general election was held on Tuesday, November 6, 2018.Turnout by county:
| County | Registered voters[3] | Ballots cast[4] | Turnout (%) |
|---|---|---|---|
| Belknap County | 47,856 | 27,229 | 56.90% |
| Carroll County | 40,166 | 24,336 | 60.59% |
| Cheshire County | 60,018 | 32,789 | 54.63% |
| Coos County | 20,595 | 11,788 | 57.23% |
| Grafton County | 71,748 | 40,758 | 56.81% |
| Hillsborough County | 282,659 | 164,337 | 58.14% |
| Merrimack County | 113,433 | 65,887 | 58.08% |
| Rockingham County | 244,859 | 141,565 | 57.81% |
| Strafford County | 98,529 | 54,072 | 54.88% |
| Sullivan County | 29,141 | 17,453 | 59.89% |
| Totals | 1,009,004 | 580,214 | 57.50% |
New Hampshire held no election for theUnited States Senate in 2018, as the state is not represented in the Senate by a seat ofClass 1.
New Hampshire's two seats in theUnited States House of Representatives were up for election. Both seats were retained by the Democratic Party.
Incumbent RepublicanChris Sununu was reelected against Democratic nomineeMolly Kelly.
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Republican | Chris Sununu (incumbent) | 302,764 | 52.78% | +3.94% | |
| Democratic | Molly Kelly | 262,359 | 45.74% | −0.83% | |
| Libertarian | Jilletta Jarvis | 8,197 | 1.43% | −2.88% | |
| n/a | Write-ins | 282 | 0.05% | −0.23% | |
| Total votes | 573,602 | 100.0% | N/A | ||
| Republicanhold | |||||
All five seats of the New Hampshire Executive Council were up for election. Democrats gained one seat, and thus achieved a 3–2 majority.
All 24 seats of the New Hampshire Senate were up for election. Democrats achieved a 14–10 majority.
All 400 seats of the New Hampshire House of Representatives were up for election. Democrats achieved a 234–166 majority.