John James Jenkins (August 24, 1843 – June 10, 1911) was an English American immigrant, lawyer, judge, and Republican politician.

[3] At the outbreak of the American Civil War, Jenkins, then seventeen years old, volunteered for service with the Union Army against his parents' wishes.

The 6th Wisconsin Infantry was a component of the Iron Brigade of the Army of the Potomac throughout the war, and Jenkins participated in nearly all the regiment's marches and battles, including Gainesville, Antietam, Gettysburg, and Ulysses S. Grant's Overland Campaign.

[3] After the war, Jenkins returned to Baraboo and was employed as a raftsman on the Wisconsin River, running timber from Germantown and Grand Rapids to St. Louis.

He was elected to a full term in 1873, but resigned in 1876 after he was appointed United States Attorney for the Wyoming Territory by U.S. President Ulysses S.

Lenroot accused Jenkins of being a tool of the reactionary old-guard Republicans, due to his close association with House Speaker Joseph Gurney Cannon.

Jenkins returned for one final public service in 1910, when President William Howard Taft appointed him to serve a four-year term as United States district judge for Puerto Rico.