John Brooks Henderson (November 16, 1826 – April 12, 1913) was an American attorney and politician who represented Missouri in the United States Senate from 1862 to 1869.

As a Senator, Henderson is most noted for co-authoring the Thirteenth Amendment to the United States Constitution, which prohibited the practice of slavery except as punishment for crime.

After leaving the Senate, Henderson also served as the first special prosecutor in United States history, investigating the Whiskey Ring until he was fired by President Ulysses S. Grant.

Born near Danville, Virginia, he moved with his parents to Lincoln County, Missouri, studied on his own while a farm hand, taught school, was admitted to the bar in 1844, and practiced.

In Butler's hearings, and in subsequent inquiries, there was increasing evidence that some acquittal votes were acquired by promises of patronage jobs and cash cards.