| Thomas B. Dunstan | |
| Office1: | 30th Lieutenant Governor of Michigan |
| Governor1: | Hazen S. Pingree |
| Term Start1: | January 1, 1897 |
| Term End1: | January 1, 1899 |
| Predecessor1: | Joseph R. McLaughlin |
| Successor1: | Orrin W. Robinson |
| State Senate2: | Michigan |
| District2: | 32nd |
| Term Start2: | 1889 |
| Term End2: | 1890 |
| Predecessor2: | Jay Abel Hubbell |
| Successor2: | John H. D. Stevens |
| State House3: | Michigan |
| District3: | Ontonagon County |
| Term Start3: | 1883 |
| Term End3: | 1884 |
| Birth Date: | 4 January 1850 |
| Birth Place: | Camborne, Cornwall, England |
| Death Place: | Chicago, Illinois |
| Party: | Republican |
Thomas B. Dunstan (January 4, 1850 – May 23, 1902) was an American politician who served as the 30th lieutenant governor of Michigan from 1897 to 1899. He previously served in the Michigan House of Representatives from the Ontonagon district from 1883 to 1884 and in the Michigan Senate from the 32nd district from 1889 to 1890.[1] [2] he died at age 52 in Chicago.