Otto Arthur Rothert (June 21, 1871 - March 28, 1956) was a German-American historian.
He was born in Huntingburg, Indiana, the youngest of five children of Herman Rothert and Franziska (Webert) Rothert, both of whom emigrated to the United States from Germany in 1844. The family moved to Louisville, Kentucky in 1889, where Herman Rothert operated a tobacco exporting business. Following graduation from the University of Notre Dame in 18992 with a science major, Otto Rothert worked for his father and then his brother in the tobacco industry before becoming a hotel clerk. In 1904 and 1905 he toured the western states extensively, as well as Hawaii and Mexico, and sent descriptive articles to the Huntingburg Independent for publication. On his return he wrote articles for the Muhlenberg Sentinel and the Greenville Record on the history of Muhlenberg County, where his family owned 2,600 acres. He also published his classic History of Muhlenberg County in 1913.
In 1908 Rothert became a member of the Filson Club, where he read several of his papers on historical topics, and was elected secretary of the club in 1917. In that role he edited books in the Filson Club publication series, arranged the annual lecture series, and edited the Filson Club History Quarterly from 1928 onwards. In addition to The Outlaws of Cave-in Rock (1924), Rothert’s published books included The Story of a Poet: Madison Cawein (1921) and The Filson Club and Its Activities, 1884-1922 (1922). He was known as “Uncle Otto” among the emerging Kentucky historians of the 1920’s such as Holman Hamilton, Hambleton Tapp, Thomas D. Clark and J. Winston Coleman.
Otto Rothert retired in 1945 and passed away in 1956 in Greenville, Kentucky. He was buried in Fairmount Cemetery in Huntingburg, Indiana.