"Oh Shenandoah" (also called "Shenandoah", "Across the Wide Missouri", "Rolling River", "Oh, My Rolling River", "World of Misery") is a traditional folk song, sung in the Americas, of uncertain origin, dating to the early 19th century.

The song "Shenandoah" appears to have originated with American and Canadian voyageurs or fur traders traveling down the Missouri River in canoes and has developed several different sets of lyrics. Some lyrics refer to the Oneida chief Shenandoah and a canoe-going trader who wants to marry his daughter. By the mid 1800s versions of the song had become a sea shanty heard or sung by sailors in various parts of the world. The song is number 324 in the Roud Folk Song Index.

Other variations (due to the influence of its oral dispersion among different regions) include the Caribbean (St. Vincent) version, "World of Misery", referring not to an "Indian princess" but to "the white mullata".

Until the 19th century, only adventurers who sought their fortunes as trappers and traders of beaver fur ventured into the lands of the indigenous peoples as far west as the Missouri River. Most of these French colonial "voyageurs" in the fur trade era were loners who became friendly with, and sometimes married, Native Americans. Some lyrics of this song heard by and before 1860 tell the story of a trader who fell in love with the daughter of the Oneida Iroquois chief Shenandoah (1710–1816) who lived in the central New York state town of Oneida Castle. He was a co-founder of the Oneida Academy which became Hamilton College in Clinton, New York, and is buried on the campus grounds.

["Shenandoah"] probably came from the American or Canadian voyageurs, who were great singers ... . In the early days of America, rivers and canals were the chief trade and passenger routes, and boatmen were an important class. Shenandoah was a celebrated Indian chief in American history, and several towns in the States are named after him. Besides being sung at sea, this song figured in old public school collections.

The canoe-going fur-trading voyageurs were great singers, and songs were an important part of their culture. In the early 19th century flatboatmen who plied the Missouri River were known for their shanties, including "Oh Shenandoah". Sailors heading down the Mississippi River picked up the song and made it a capstan shanty that they sang while hauling in the anchor. This boatmen's song found its way down the Mississippi River to American clipper ships—and thus around the world.

The song had become popular as a sea shanty with seafaring sailors by the mid 1800s. A version of the song called "Shanadore" was printed in Capt. Robert Chamblet Adams' article "Sailors' Songs" in the April 1876 issue of The New Dominion Monthly. He also included it in his 1879 book On Board the "Rocket". "Shanadore" was later printed as part of William L. Alden's article "Sailor Songs" in the July 1882 issue of Harper's New Monthly Magazine, and in the 1892 book Songs that Never Die. Alfred Mason Williams' 1895 Studies in Folk-song and Popular Poetry called it a "good specimen of a bowline chant".

Percy Grainger recorded Charles Rosher of London England singing Shenandoah in 1906 and the recording is available online via the British Library Sound Archive. A recording sung by former shantyman Stanley Slade of Bristol, England, in 1943 is also publicly available.