Joseph Clay Stiles Blackburn (October 1, 1838 - September 12, 1918) was a Democratic Representative and Senator from Kentucky. He was the younger brother of Kentucky governor Luke P. Blackburn. Blackburn, a skilled and spirited orator, was also a prominent trial lawyer known for his skill at swaying juries.
He was born near Spring Station, Kentucky. He attended Sayres Institute in Frankfort and graduated from Centre College in Danville in 1857. He studied law in Lexington and was admitted to the bar in 1858. He practiced in Chicago until 1860 when he returned to Woodford County, Kentucky and entered the Confederate Army as a private in 1861.
A staff officer, by the end of the Civil War Blackburn had attained the rank of lieutenant colonel. After the war he settled in Arkansas where he was engaged as a lawyer and a planter in Desha County until 1868 when he returned to Kentucky and opened law offices in Versailles.
He was a member of the State house of representatives from 1871 to 1875. He was then elected as a Democrat to the Forty-fourth and to the four succeeding Congresses (March 4 1875 - March 3 1885). He was the chairman of the Committee on the District of Columbia (Forty-fifth Congress) and the Committee on Expenditures in the Department of War (Forty-fifth and Forty-sixth Congresses).
He was elected to the United States Senate in 1885, was reelected in 1890, and served from March 4 1885, to March 3 1897. He failed to be reelected in 1896. He was the chairman of the Committee on Rules (Fifty-third Congress). He was once again elected to the United States Senate in 1900 and served from March 4 1901 to March 3 1907, but failed in his next election bid in 1906. Loosely associated with the free-silver wing of the Democratic party, he was well-known nationally and his name was placed in nomination for the presidency in 1896.
He died in Washington, D.C. and was interred in the State Cemetery in Frankfort.