| Office1: | Member of the U.S. House of Representatives from Massachusetts |
| Term Start1: | December 6, 1802 |
| Term End1: | March 3, 1805 |
| Predecessor1: | Silas Lee |
| Successor1: | Orchard Cook |
| Constituency1: | 12th district (1802–1803) 16th district (1803–1805) |
| Office2: | Member of the Massachusetts House of Representatives |
| Term2: | 1801-1811 |
| Birth Date: | 1 July 1776 |
| Birth Place: | Cambridge, Province of Massachusetts Bay, British America |
| Death Place: | Bangor, Maine, U.S. |
| Alma Mater: | Harvard College |
| Profession: | lawyer |
Samuel Thatcher (July 1, 1776 – July 18, 1872) was a member of the United States House of Representatives from Massachusetts.
He was born in Cambridge in the Province of Massachusetts Bay on July 1, 1776; was graduated from Harvard University in 1793; studied law; was admitted to the bar in 1797 and commenced practice in New Gloucester (then in Massachusetts' District of Maine); moved to Warren in 1800; member of the Massachusetts house of representatives 1801–1811; was elected as a Federalist to the Seventh Congress to fill the vacancy caused by the resignation of Silas Lee; reelected to the Eighth Congress and served from December 6, 1802, to March 3, 1805; sheriff of Lincoln County, 1814–1821; member of the Maine house of representatives in 1824; moved to Bangor, Maine, in 1860, and died there July 18, 1872; interment in Bangor's Mount Hope Cemetery.