| Election Name: | 1908 Democratic Senate primary in South Carolina |
| Country: | South Carolina |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1908 United States Senate special election in South Carolina |
| Previous Year: | 1908 (special) |
| Next Election: | 1914 United States Senate election in South Carolina |
| Next Year: | 1914 |
| Election Date: | September 8, 1908 |
| Image1: | File:Senator Ellison DuRant Smith.jpg |
| Nominee1: | Ellison D. Smith |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 69,318 |
| Percentage1: | 63.6% |
| Nominee2: | John Gary Evans |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 39,655 |
| Percentage2: | 36.4% |
| U.S. Senator | |
| Before Election: | Frank B. Gary |
| Before Party: | Democratic Party (United States) |
| After Election: | Ellison D. Smith |
| After Party: | Democratic Party (United States) |
The 1909 South Carolina United States Senate election was held on January 26, 1909. Its outcome was determined by a Democratic Party primary election held on August 25 and September 8, 1908. Interim Senator Frank B. Gary, who had been elected to complete the unfinished term of the late Senator Asbury Latimer, did not run for re-election. Democrat Ellison D. Smith won the Democratic primary and was elected by the General Assembly for a six-year term.
Prior to the ratification of the Seventeenth Amendment to the United States Constitution, U.S. senators were elected by state legislatures rather than the direct election by the people of the state. However, the South Carolina Democratic Party organized non-binding primary elections for the U.S. Senate beginning in 1896, and the South Carolina General Assembly confirmed the choice of the Democratic voters.
Ellison D. Smith, an official in the Cotton Association and often called "Cotton Ed", entered the Democratic primary but found himself in early trouble when he promised that cotton would rise to eighteen cents and it did not occur. However, his rhetorical skills allowed him to take command of the stump and attract voters to his campaign.
Former Governor John Gary Evans was making his fourth straight attempt for the Senate seat and received the private support of Senator Ben Tillman. The tide of Tillmanism had receded in the state and the public endorsement by Tillman would doom a candidate's prospects. Smith and Evans emerged as the top two candidates were to face each other in a runoff election on September 8. Evans once again failed to carry the day and Smith scored a resounding victory.
Smith was elected unanimously by the South Carolina Legislature on January 26, 1909.