Isaac Appleton III was born 30 May 1731 in Ipswich, Essex County, Massachusetts to Isaac Appleton (1704-1794) and Elizabeth Sawyer (1710-1785) and died 25 February 1806 New Ipswich, Hillsborough County, New Hampshire of unspecified causes. He married Mary Adams (1741-1827) 24 April 1760 in Concord, Middlesex County, Massachusetts.
Children
| Name | Birth | Death | Joined with |
| Isaac Appleton (1762-1853) | |||
| Joseph Appleton (1764-1791) | |||
| Samuel Appleton (1766-1853) | 22 June 1766 New Ipswich, Hillsborough County, New Hampshire | 12 July 1853 Boston, Suffolk County, Massachusetts | Mary Lekain (1788-1870) |
| Aaron Appleton 91768-1852) | |||
| Dolly Appleton (1770-1859) | |||
| Moses Appleton (1773-1849) | |||
| Mary Appleton (1775-1853) | |||
| Ebenezer Appleton (1777-1780) | |||
| Nathan Appleton (1779-1861) | 6 October 1779 New Ipswich, Hillsborough County, New Hampshire | 14 July 1861 Boston, Suffolk County, Massachusetts | Maria Theresa Gold (1786-1833) Harriet Coffin Sumner (1802-1867) |
| Emily Appleton (1781-1809) | |||
| Ebenezer Appleton (1784-1833) | 7 June 1784 New Ipswich, Hillsborough, New Hampshire | 29 April 1833 Cambridge, Middlesex County, Massachusetts | Sarah Patterson (1788-1837) |
| Emma Appleton (1787-1791) | |||
Siblings
| Name | Birth | Death | Joined with |
| Isaac Appleton (1731-1806) | 30 May 1731 Ipswich, Essex County, Massachusetts | 25 February 1806 New Ipswich, Hillsborough County, New Hampshire | Mary Adams (1741-1827) |
| Francis Appleton (1733-1816) | 25 March 1733 Ipswich, Essex County, Massachusetts | 29 January 1816 New Ipswich, Hillsborough County, New Hampshire | Elizabeth Hubbard (1730-1815) |
| Elizabeth Appleton (1736-1817) | |||
| Samuel Appleton (1738-1819) | 7 August 1738 Ipswich, Essex County, Massachusetts, United States | 15 May 1819 Ipswich, Essex County, Massachusetts, United States | Mary White (1732-1834) |
| Thomas Appleton (1741-1830) | |||
| John Appleton (1742-1829) | |||
| Daniel Appleton (1745-1836) | |||
| William Appleton (1747-1785) | |||
| Mary Appleton (1749-1828) | |||
| Joseph Appleton (1751-1795) | 9 June 1751 Ipswich, Essex County, Massachusetts, United States | 25 July 1795 Brookfield, Worcester County, Massachusetts, United States | Mary Hook (1756-1842) |