Coleman Livingston Blease (October 8, 1868 – January 19, 1942) was an American politician of the Democratic Party who served as the 89th governor of South Carolina from 1911 to 1915 and represented the state in the United States Senate from 1925 to 1931. Blease was the political heir of Benjamin Tillman. He led a political revolution in South Carolina by building a political base of white textile mill workers from the state's upcountry region. He was a staunch white supremacist and frequently used inflammatory rhetoric to appeal to racial animosities among white voters.

As governor and later senator, Blease opposed civil rights for African Americans, spoke in favor of lynching, and resisted educational opportunities for Black citizens. In the Senate, he introduced legislation targeting interracial relationships and criticized efforts at racial inclusion in public life. He was also instrumental in the passage of Section 1325 of the U.S. immigration code, which criminalized unlawful entry into the United States—a provision that remains in effect.

Blease was born to Henry Horatio Blease (1832–1892) and Mary Ann Livingston Blease (1830–1874) near the town of Newberry, South Carolina, on October 8, 1868, the year that South Carolina's new Reconstruction constitution was adopted, and Black Americans began participating in political life. He grew up in his father's hotel which led him to be uncommonly social. He was educated at Newberry College, the University of South Carolina, and Georgetown University, where he graduated from the law department in 1889. At the University of South Carolina, Blease was expelled for plagiarism and always carried a grudge against the university.

After his schooling was complete, Blease returned to Newberry to practice law and to enter politics. He began his political career in the South Carolina House of Representatives in 1890 as a Democrat and protégé of Benjamin Tillman. In 1895, the state legislature ratified a new constitution that essentially disfranchised Black people, thus crippling the state's Republican Party, which they supported. The state then had a one-party system, run by the Democrats.

Blease's rise to power, as he moved from the South Carolina House of Representatives to the South Carolina Senate in 1900, was built on the support of both the sharecroppers and white mill workers, then an increasingly-important segment of the electorate in South Carolina. But it was not a straightforward rise, Blease lost his seat in the legislature in 1894 and his attempt to re-gain it in 1896. And while he ultimately obtained a state senate seat in 1900, he subsequently lost races to become the Democratic nominee for governor in 1904 and 1906.

In 1910, Blease was elected mayor of Newberry and held that position until November of that year, when he was elected governor of South Carolina.

Critics and allies of Blease alike used the term Bleasism to "designate the political uprising of first-generation South Carolina millworkers" led by Blease in 1910. The political uprising was different from the one led by Ben Tillman a generation earlier. Whereas Tillman sought agricultural reform and drew his political support from South Carolina's white farmers and planters, Blease was anti-reform and drew his support from white textile mill workers. The movement Blease led was largely characterized by white supremacy and not social policy. But it shared the same enemies as Tillmanism: the newspapers, the railroads, corporations, Charleston aristocrats, and urban businessmen.

Bleasism was made possible by the sociopolitical change South Carolina underwent at the turn of the twentieth century. For instance, in 1880, the state had close to a dozen textile mills, but in 1900 the number had grown to 115. The work force of the mills also changed, becoming increasingly more male each year. Because South Carolina was one of the few Southern states at the time that did not disenfranchise poor white men, Blease actively courted the workers of these mills and built a devoted political base from the men, who hung his photo in their homes and named their children after him.