The 2020 presidential campaign of Michael Bloomberg, a businessman and former mayor of New York City, began when he filed a statement of candidacy with the Federal Election Commission for the office of President of the United States as a member of the Democratic Party on November 21, 2019. His principal campaign committee was called "Mike Bloomberg 2020, Inc." The campaign officially launched on November 24, 2019, in Virginia, later than most other candidates for the Democratic nomination.

Presidential primaries and caucuses were organized by the Democratic Party to select the 3,979 pledged delegates to the 2020 Democratic National Convention held on August 17–20 to determine the party's nominee for president in the 2020 United States presidential election. The elections took place in all 50 U.S. states, the District of Columbia, five U.S. territories, and through Democrats Abroad, and occurred between February 3 and August 11.