The Chicago Tribune is a daily newspaper based in Chicago, Illinois, United States, owned by Tribune Publishing. Founded in 1847, and formerly self-styled as the "World's Greatest Newspaper" (a slogan for which WGN radio and television are named), it remains the most-read daily newspaper in the Chicago metropolitan area and the Great Lakes region. In 2017, it had the sixth-highest circulation of any American newspaper.

In the 1850s, under Joseph Medill, the Chicago Tribune became closely associated with the Illinois politician Abraham Lincoln, and the Republican Party's progressive wing. In the 20th century, under Medill's grandson Robert R. McCormick, it achieved a reputation as a crusading paper with a decidedly more American-conservative anti-New Deal outlook, and its writing reached other markets through family and corporate relationships at the New York Daily News and the Washington Times-Herald. The 1960s saw its corporate parent owner, Tribune Company, reach into new markets. In 2008, for the first time in its over-a-century-and-a-half history, its editorial page endorsed a Democrat, Illinoisan Barack Obama, for U.S. president.

Originally published solely as a broadsheet, the Tribune announced on January 13, 2009, that it would continue publishing as a broadsheet for home delivery, but would publish in tabloid format for newsstand, news box, and commuter station sales. This change, however, proved to be unpopular with readers, and in August 2011, the Tribune discontinued the tabloid edition, returning to its established broadsheet format through all distribution channels.

The Tribune's masthead displays the American flag, in reference to the paper's former motto, "An American Paper for Americans". The motto is no longer displayed on the masthead, where it was placed below the flag.

The Tribune was owned by parent company Tribune Publishing. In May 2021, Tribune Publishing was acquired by Alden Global Capital, which operates its media properties through Digital First Media.