| Jacob Hersey Loud | |
| Birth Date: | February 5, 1802 |
| Nationality: | American |
| Spouse: | Elizabeth Loring |
| Term Start: | 1866 |
| Term End: | 1871 |
| Governor: | Alexander H. Bullock William Claflin |
| Term Start2: | 1864 |
| Term End2: | 1865 |
| Term Start3: | 1863 |
| Term End3: | 1863 |
| Term Start4: | 1853 |
| Term End4: | 1855 |
| Governor4: | John H. Clifford Emory Washburn |
| Term Start5: | 1830 |
| Term End5: | 1852 |
| Predecessor5: | Beza Hayward |
| Appointed5: | Levi Lincoln Jr. |
| Title6: | Member of the Plymouth, Massachusetts Board of Selectmen |
| Title7: | Moderator of the Plymouth, Massachusetts Town Meeting |
| Profession: | Lawyer |
Jacob Hersey Loud (February 5, 1802 – February 2, 1880) was a Massachusetts lawyer and an American politician who served as a member of the Massachusetts House of Representatives, the Massachusetts Senate, for twenty two years as the Register of Probate for Plymouth County, Massachusetts, and twice as the Treasurer and Receiver-General of Massachusetts.