Robber Baron is a pejorative term used for a powerful 19th century businessman. By the 1890s, the term was typically applied to businessmen who were viewed as having used questionable practices to amass their wealth. It combines the sense of criminal ("robber") and illegitimate aristocracy ("baron"). U.S. political and economic commentator Matthew Josephson popularized the term during the Great Depression in a 1934 book by the same title.

List of businessmen who were called robber barons

• John Jacob Astor III, fur trader and real estate investor
• George Fisher Baker
• Charles T. Barney
• Wellington R. Burt
• Andrew Carnegie, railway entrepreneur and steel manufacturer
• Jay Cooke, railroad executive
• Charles Crocker, railroad executive
• Daniel Drew, railroad executive
• James Buchanan Duke, energy and tobacco industry executive
• William Fargo
• James Fisk, steel manufacturer
• Henry Flagler, oil industrialist and railroad executive
• Henry Clay Frick, steel manufacturer
• John Warne Gates, barbed wire promoter and oil industrialist
• Jay Gould, railroad executive
• E. H. Harriman, railroad executive
• F. Augustus Heinze
• James J. Hill
• Mark Hopkins, railroad executive
• Collis Potter Huntington
• Hynek Krušina of Lichtenburg
• Theodore Judah
• Andrew W. Mellon, banker and politician
• Richard B. Mellon
• William Henry Moore
• J. P. Morgan, banker, financier, and railway entrepreneur
• Charles W. Morse
• Henry B. Plant, railroad executive
• John D. Rockefeller, oil industrialist and railway entrepreneur
• Charles M. Schwab, steel manufacturer
• Joseph Seligman, banker, financier, and railway entrepreneur
• Samuel Slater
• John D. Spreckels, sugar manufacturer, railway entrepreneur, and real estate investor
• Leland Stanford, railroad executive and politician
• James Stillman
• Cornelius Vanderbilt, shipping entrepreneur and railroad executive
• William Henry Vanderbilt
• Henry Villard
• Henry Wells
• Cassius Milton Wicker
• Charles Yerkes, railway entrepreneur