Israel Washburn Sr. (1784–1876) was a Massachusetts politician and brother of Reuel Washburn. He married Martha Benjamin "Patty" Washburn and had eleven children with her, including seven sons (one child died shortly after birth, however). Several went on to pursue politics as well: Israel Washburn Jr., Elihu B. Washburne, Cadwallader C. Washburn, and William D. Washburn. Charles Ames Washburn was an elector and a diplomat.
Washburn served in the Massachusetts House of Representatives 1815–1816 and 1818–1819.