Frederick William Lehmann (February 28, 1853 – September 12, 1931) was an American lawyer, politician, United States Solicitor General, and rare book collector.

His father, Friedrich Wilhelm Lehmann, emigrated to Cincinnati, Ohio, when Frederick was two, where he ruled the family with an iron hand.

In his teens, at the urging of his fellow sheep men, he took the stump for presidential candidate Horace Greeley and gave his first political speech.

In 1890, he moved with his family to St. Louis, Missouri, and continued to represent the Wabash while building a general law practice.

Inscribed in the office rotunda of the Attorney General is Lehmann's famous saying, when a judge had remarked that he seemed to be supporting the opposing side: "The United States wins its point whenever justice is done its citizens in the courts."

He was a bibliophile and he collected rare first editions of Charles Dickens, Robert Burns and others, and artworks of Aubrey Beardsley, George Cruikshank and Thomas Rowlandson.

His published works included: John Marshall (1901), The Lawyer in American History (1906), Abraham Lincoln (1908), Conservatism in Legal Procedure (1909), Prohibition (1910), and The Law and the Newspaper (1917).

Three special collections at Olin Library, Washington University in St. Louis, include a selection of Lehmann's legal papers (including his time as Solicitor General), a collection of historic manuscript letters of notable people, and rare editions of works of Robert Burns and others.