The JamesYounger Gang was a notable 19th-century gang of American outlaws that revolved around Jesse James and his brother Frank James. The gang was based in the state of Missouri, the home of most of the members.

Membership fluctuated from robbery to robbery, as the outlaws' raids were usually separated by many months. As well as the notorious James brothers, at various times it included the Younger brothers (Cole, Jim, John, and Bob), John Jarrett (married to the Youngers' sister Josie), Arthur McCoy, George Shepherd, Oliver Shepherd, William McDaniel, Tom McDaniel, Clell Miller, Charlie Pitts (born Samuel A. Wells), and Bill Chadwell (alias Bill Stiles).

The JamesYounger Gang had its origins in a group of Confederate bushwhackers that participated in the bitter partisan fighting that wracked Missouri during the American Civil War. After the war, the men continued to plunder and murder, though the motive shifted to personal profit rather than in the name of the Confederacy. The loose association of outlaws did not truly become the "JamesYounger Gang" until 1868 at the earliest, when the authorities first named Cole Younger, John Jarrett, Arthur McCoy, George Shepherd and Oliver Shepherd as suspects in the robbery of the Nimrod Long bank in Russellville, Kentucky.

The JamesYounger Gang dissolved in 1876, following the capture of the Younger brothers in Minnesota during the unsuccessful attempt to rob the Northfield First National Bank. Three years later, Jesse James organized a new gang, including Clell Miller's brother Ed and the Ford brothers (Robert and Charles), and renewed his criminal career. This career came to an end in 1882 when Robert Ford shot James from behind, killing him.

For nearly a decade following the Civil War, the JamesYounger Gang was among the most feared, most publicized, and most wanted confederations of outlaws on the American frontier. Though their crimes were reckless and brutal, many members of the gang commanded a notoriety in the public eye that earned the gang significant popular support and sympathy. The gang's activities spanned much of the central part of the country; they are suspected of having robbed banks, trains, and stagecoaches in at least eleven states: Missouri, Kentucky, Tennessee, Iowa, Kansas, Minnesota, Texas, Arkansas, Louisiana, Alabama, and West Virginia.

Northfield is a city in Dakota and Rice counties in the State of Minnesota. It is mostly in Rice County, with a small portion in Dakota County. The population was 20,790 at the 2020 census.