| Horace T. Cahill | |
| Order: | 54th |
| Office: | Lieutenant Governor of Massachusetts |
| Term Start: | January 5, 1939 |
| Term End: | January 3, 1945 |
| Governor: | Leverett Saltonstall |
| Predecessor: | Francis E. Kelly |
| Successor: | Robert F. Bradford |
| Office1: | Speaker of the Massachusetts House of Representatives |
| Term Start1: | 1937 |
| Term End1: | 1938 |
| Predecessor1: | Leverett Saltonstall |
| Birth Date: | 12 December 1894 |
| Death Place: | Quincy, Massachusetts |
| Party: | Republican |
Horace Tracy Cahill (December 12, 1894 – August 22, 1976) was an American politician who served in the Massachusetts House of Representatives, as Speaker of the Massachusetts House of Representatives and, from 1939 to 1945, as the 54th lieutenant governor of Massachusetts. In 1944 Cahill was the unsuccessfully Republican candidate for governor.
Cahill was born to George William and Alice Gertrude (Dallon) Cahill in New York City on December 12, 1894.[1] After his father's death Cahill moved with his family to Boston, Massachusetts.[1]
Prior to becoming a politician, Cahill served in the United States Army in World War I.[2] From 1947 to 1973 he was a Superior Court judge. There is an auditorium in Braintree, Massachusetts named in his honor.[3] [4]