| John S. Barnes Jr. | |
| State Senate: | New Hampshire |
| District: | 17th |
| Term Start1: | December 6, 2000 |
| Term End1: | December 5, 2012 |
| Predecessor1: | Mary E. Brown |
| Successor1: | John Reagan |
| Term Start2: | December 2, 1992 |
| Term End2: | December 2, 1998 |
| Predecessor2: | Gordon J. Humphrey |
| Successor2: | Mary E. Brown |
| State House3: | New Hampshire |
| District3: | Rockingham 6th |
| Term Start3: | December 7, 1988 |
| Term End3: | December 2, 1992 |
| Birth Date: | 21 August 1931 |
| Birth Place: | Arlington, Massachusetts, U.S. |
| Spouse: | Frances |
| Profession: | Retired business owner |
| Religion: | Roman Catholic --> |
| Party: | Republican |
John S. Barnes Jr. (born August 21, 1931) is an American politician who served in the New Hampshire Senate for the 17th district, from 1992 to 1998 and again from 2000 to 2012. A member of the Republican Party, he previously served as a member of the New Hampshire House of Representatives from 1988 until 1992.
Barnes won the New Hampshire primary for Vice President of the United States in 2008.[1] The following year, he co-sponsored a bill which abolished the vice-presidential preference ballot. The bill passed both houses of the state legislature and took effect in 2012.[2]