John Nicholas Ringling was an American entrepreneur who is the best known of the seven Ringling brothers, five of whom merged the Barnum & Bailey Circus with their own Ringling Bros. World's Greatest Shows to create a virtual monopoly of traveling circuses and helped shape the modern circus. In addition to owning and managing many of the largest circuses in the United States, he was also a rancher, a real estate developer and art collector. He was inducted into the Florida Artists Hall of Fame in 1987.

The Ringling brothers were five American siblings who transformed their small touring company of performers into one of the largest circuses in the United States during the late 19th and early 20th centuries. Four brothers were born in McGregor, Iowa: Alfred T., Charles, John and Henry William, and the family lived in McGregor for twelve years, from 1860 until 1872. The Ringling family then moved to Prairie du Chien, Wisconsin, and finally settled in Baraboo, Wisconsin, in 1875. They were of German and French descent, the children of harness maker Heinrich Friedrich August Ringling (1826–1898) of Hanover, and Marie Salome Juliar (1833–1907) of Ostheim, in Alsace. While there were seven Ringling brothers, Alfred, Charles, John, Al and Otto Ringling were the main brothers in charge of the circus shows. All of the brothers were Freemasons. In 1919, they merged their Ringling Brothers Circus with America's other leading circus troupe, Barnum and Bailey, ultimately creating the Ringling Bros. and Barnum & Bailey Circus, which has operated continuously since except for a hiatus from 2017 to 2022.