The Secretary of State of New Hampshire is a constitutional officer in the U.S. state of New Hampshire and serves as the exclusive head of the New Hampshire Department of State. The Secretary is third in line for succession as acting Governor of New Hampshire, following the state's President of the Senate and Speaker of the House. The Secretary oversees all state elections, including certifying the results, and keeps the official records of the state. The Secretary is, by statute, the only person who can authorize use of the State Seal.

Bill Gardner is an American politician who was the New Hampshire Secretary of State from 1976 to 2022. In that role, he was in charge of the department that oversees all general elections, primary elections, voter registration and recounts within the state, including the New Hampshire primary. His tenure is the longest of any secretary of state in U.S. history. He is a member of the Democratic Party.