John Laurens Manning Irby
United States Senator from South Carolina
In office March 4, 1891 – March 4, 1897
Preceded by	Wade Hampton III
Succeeded by	Joseph H. Earle
36th Speaker of the South Carolina House of Representatives
In office November 25, 1890 – December 23, 1890
Preceded by	James Simons, Jr.
Succeeded by	Ira B. Jones
Member of the South Carolina House of Representatives from Laurens County
In office November 23, 1886 – December 23, 1890
Personal details
Born	(1854-09-10)September 10, 1854 Laurens, South Carolina
Died	December 9, 1900(1900-12-09) (aged 46) Laurens, South Carolina
Political party	Democratic
Alma mater	Princeton University University of Virginia

John Laurens Manning Irby (September 10, 1854 – December 9, 1900) was a United States senator from South Carolina. Born in Laurens, he attended Laurensville Male Academy (Lauren), Princeton College (Princeton, New Jersey in 1870-1871, and the University of Virginia at Charlottesville from 1871 to 1873. He studied law, was admitted to the bar in 1875, commenced practice at Cheraw, and returned to Laurens. He was appointed lieutenant colonel of the South Carolina Militia in 1877 and that year was also intendant of Lauren. He was a member of the South Carolina House of Representatives from 1886 to 1892, serving as speaker in 1890.

Irby was elected as a Democrat to the U.S. Senate and served from March 4, 1891, to March 4, 1897; he was not a candidate for reelection. While in the Senate, he was chairman of the Committee on Transportation Routes to the Seaboard (Fifty-third Congress). Irby was subsequently an unsuccessful candidate for election to the United States Senate in 1897 to fill the vacancy caused by the death of his cousin Joseph H. Earle, and was a delegate to the State constitutional convention in 1895. He resumed the practice of law and also engaged in agricultural pursuits; he died in Laurens in 1900; interment was in the City Cemetery.

Joseph H. Earle, Irby's cousin, and Elias Earle, his great-grandfather, had both been members of the U.S. Congress.

• United States Congress. "John L. M. Irby (id: I000027)". Biographical Directory of the United States Congress.