The Signer's House and Matthew Thornton Cemetery are a pair of historic properties in Merrimack, New Hampshire, United States. It consists of a house, once owned by Matthew Thornton, a signer of the United States Declaration of Independence, and the adjacent cemetery in which he is buried. The house is a two-story Georgian style double house, and is the only surviving house of the period in Merrimack. It was owned by Thornton from 1780 to 1797, when he sold it to his son James. The cemetery, located across the Daniel Webster Highway from the house, is also Merrimack's first cemetery, with the oldest gravestone marked 1742.