John Brough (rhymes with "huff") (September 17, 1811 - August 29, 1865) was a War Democrat politician from Ohio. He served as the 26th Governor of Ohio.

Born in Marietta, Ohio, Brough was orphaned at the age of 11, became a printer's apprentice, and received three years of part-time education at Ohio University. He rose to become a newspaper publisher in Marietta and then Lancaster. He served two years as clerk of the Ohio Senate before being elected to the Ohio House of Representatives in 1837, representing the Fairfield-Hocking district, and served from 1838-1839, when he took office as State Auditor, serving from 1839-1845.

Brough then moved to Indiana, where he entered the railroad business and became president of the Bellefontaine Line. Ohio Republicans and War Democrats dissatisfied with the leadership of Ohio Gov. David Tod turned to Brough after he made a strongly pro-Union speech in his hometown of Marietta on June 10, 1863. He was elected to the Ohio governorship that fall on a pro-Union ticket, defeating Copperhead leader Clement Vallandigham and prompting President Abraham Lincoln to wire Brough, "Glory to God in the Highest. Ohio has saved the Union."

Brough took office in January 1864. Ohio historian Walter Havighurst described Brough as being "a big bull of a man with driving energy," and Richard H. Abbott wrote that he "had a reputation for rough and ready politics with a temperament to match... [he was] a blunt, outspoken, rude man who loved to chew tobacco [and thus] presented quite a contrast with his two handsome and dignified predecessors," William Dennison and David Tod.

As governor, Brough strongly supported the Lincoln Administration's war efforts and was key to persuading other Midwestern governors to raise 100-day regiments in early 1864 to release more seasoned troops for duty in Gen. Ulysses S. Grant's spring campaign. Ohio contributed more than 34,000 troops, and was the only one of the five participating states (the others were Indiana, Illinois, Iowa and Wisconsin) to exceed its quota. Brough supported Lincoln's reelection in 1864, despite the machinations of Ohio's favorite son Salmon P. Chase, and worked tirelessly to support the state's soldiers in the field.

With the conclusion of the war in 1865, the pro-Union alliance between Ohio's Republicans and War Democrats dissolved, and the now-dominant Republicans looked elsewhere for a candidate. On June 15, 1865, Brough announced that he would not seek the gubernatorial nomination again but would not decline it if offered; it was not. Later that summer, Brough stumbled in the State House yard, bruising his hand and badly spraining his ankle. Using a cane caused inflammation, in time, and gangrene set in. Gov. Brough died in office on August 29, 1865.

Abbott wrote that Brough "had given his full efforts to serving his state... [and did so] with energy and ability." Historian Richard C. Knopf wrote, "Whatever may be said of Brough's partisanship and his lack of personal dignity, one must assess in his favor the qualities of integrity, perseverance, and public spiritedness."