Sydney Floyd Landreth (March 27, 1885 – October 2, 1977) was an American lawyer, banker and Republican politician from Galax, Virginia who represented the 14th state senatorial district for two decades.

S. Floyd Landreth graduated from the local Woodlawn High School and then attended Washington and Lee University further up the Shenandoah Valley in Lexington, Virginia.

[4] A decade later, Tuck would become a crucial figure in the Massive Resistance movement to the United States Supreme Court decisions in Brown v. Board of Education.

Landreth was chairman of the state Republican Party in 1952, and greeted President Dwight Eisenhower during his campaign stops in southern Virginia.

Virginians' upset over Governor Thomas B. Stanley's closing of public schools, as well as census changes and changes in federal law (especially the Voting Rights Act of 1965 which the Democratic Byrd Organization vehemently opposed) eventually led to the revitalization of the state Republican Party and return of two-party democracy to the state with the election of Linwood Holton as Governor before Landreth's death.