During the U.S. Republican National Convention in Chicago, U.S. Republican Party leaders gathered in a room at the Blackstone Hotel to come to a consensus on their candidate for the U.S. presidential election, leading the Associated Press to coin the political phrase "smoke-filled room".

The 1920 Republican National Convention nominated Ohio Senator Warren G. Harding for president and Massachusetts Governor Calvin Coolidge for vice president. The convention was held in Chicago, Illinois, at the Chicago Coliseum from June 8 to June 12, 1920, with 940 delegates. Under convention rules, a majority plus one, or at least 471 of the 940 delegates, was necessary for a nomination.

The Republican Party, also known as the Grand Old Party (GOP), is a right-wing political party in the United States. One of the two major parties, it emerged as the main rival of the then-dominant Democratic Party in the 1850s, and the two parties have dominated American politics since then.

The Blackstone Hotel is a historic 290-foot (88 m) 21-story hotel on the corner of Michigan Avenue and Balbo Drive in the Michigan Boulevard Historic District in the Loop community area of Chicago, Illinois. Built between 1908 and 1910, it is on the National Register of Historic Places. The Blackstone is famous for hosting celebrity guests, including numerous U.S. presidents, for which it was known as the "Hotel of Presidents" for much of the 20th century, and for contributing the term "smoke-filled room" to political parlance.

Presidential elections were held in the United States on November 2, 1920. The Republican ticket of senator Warren G. Harding of Ohio and governor Calvin Coolidge of Massachusetts defeated the Democratic ticket of governor James M. Cox of Ohio and assistant secretary Franklin Roosevelt of New York. It was the first election held after the end of the First World War, and the first election after the ratification of the Nineteenth Amendment gave nationwide suffrage to women. It was the first presidential election to have its results broadcast by radio.