The Democratic Caucus of the United States Senate, sometimes referred to as the Democratic Conference, is the formal organization of all senators who are part of the Democratic Party in the United States Senate. For the makeup of the 118th Congress, the caucus additionally includes three independent senators who caucus with the Democrats, bringing the current total to 51 members. The central organizational front for Democrats in the Senate, its primary function is communicating the party's message to all of its members under a single banner. The present chair of the Senate Democratic Caucus is Chuck Schumer of New York.

The United States Senate is the upper chamber of the United States Congress. The United States Senate and the lower chamber of Congress, the United States House of Representatives, comprise the federal bicameral legislature of the United States. Together, the Senate and the House maintain authority under Article One of the U.S. Constitution to pass or defeat federal legislation. The Senate has exclusive power to confirm U.S. presidential appointments, approve or reject treaties, and try cases of impeachment brought by the House. The Senate and the House provide a check and balance on the powers of the executive and judicial branches of government.