Party leaders of the United States Senate

The positions of majority leader and minority leader are held by two United States senators and people of the party leadership of the United States Senate. They serve as chief spokespersons for their respective political parties, holding the majority and the minority in the chamber. They are each elected to their posts by the senators of their party caucuses: the Senate Democratic Caucus and the Senate Republican Conference.

By Senate precedent, the presiding officer gives the majority leader priority in obtaining recognition to speak on the floor. The majority leader serves as the chief representative of their party in the Senate and is considered the most powerful member of the chamber. They also serve as the chief representative of their party in the entire Congress if the House of Representatives, and thus the office of the speaker of the House, is controlled by the opposition party. The Senate's executive and legislative business is also managed and scheduled by the majority leader.

The assistant majority leader and assistant minority leader of the United States Senate, commonly called whips, are the second-ranking members of each party's leadership. The main function of the majority and minority whips is to gather votes of their respective parties on major issues. As the second-ranking members of Senate leadership, if there is no floor leader present, the whip may become acting floor leader.

The Senate of the 119th Congress is composed in 2025 of 53 Republicans, 45 Democrats, and 2 independents; both the independents caucus with the Democrats.

The leaders are Senators John Thune (R) of South Dakota and Chuck Schumer (D) of New York. The assistant leaders, or whips, are Senators John Barrasso (R) of Wyoming and Dick Durbin (D) of Illinois.

At first a Senate leader was an informal position usually an influential committee chairman, or a person of great eloquence, seniority, or wealth, such as Daniel Webster and Nelson Aldrich. By at least 1850, parties in each chamber of Congress began naming chairs, and while conference and caucus chairs carried very little authority, the Senate party floor leader positions arose from the position of conference chair.

Senate Democrats began electing their floor leaders in 1920 while they were in the minority. John W. Kern was a Democratic senator from Indiana. While the title was not official, the Senate website identifies Kern as the first Senate party leader, serving in that capacity from 1913 through 1917 (and in turn, the first Senate Democratic leader), while serving concurrently as chairman of the Senate Democratic Caucus.

In 1925, the Republicans (who were in the majority at the time) also adopted this language when Charles Curtis became the first (official) majority leader, although his immediate predecessor Henry Cabot Lodge is considered the first (unofficial) Senate majority leader. However, despite this new, formal leadership structure, the Senate leader initially had virtually no power. Since the Democrats were fatally divided into northern liberal and southern conservative blocs, the Democratic leader had even less power than his title suggested.