Jacob Harold Gallinger (28 March 1837-17 August 1918) was a member of the US House of Representatives (R-NH 2) from 4 March 1885 to 3 March 1889 (succeeding Ossian Ray and preceding Orren C. Moore) and a US Senator from 4 March 1891 to 17 August 1918 (succeeding Henry W. Blair and preceding Irving W. Drew). Born in Cornwall, Ontario, he was raised in New Hampshire and worked as a physician and surgeon in Keene, New Hampshire and Concord before being an active member of the American Institute of Homeopathy from 1868 to 1880. Gallinger went on to serve in the state house from 1872 to 1873, the state senate from 1878 to 1880, the House from 1885 to 1889, and the Senate from 1891 until his death in 1918.