Chester Trent Lott Sr. is an American lobbyist, lawyer, author, and politician who represented Mississippi in the United States House of Representatives from 1973 to 1989 and in the United States Senate from 1989 to 2007. Lott served in numerous leadership positions in both chambers of Congress as one of the first of a wave of Republicans winning seats in Southern states that had been solidly Democratic. Later in his career, he served twice as Senate Majority Leader, and also, alternately, Senate Minority Leader. In 2003, he stepped down from the position after controversy due to his praising of Senator Strom Thurmond's 1948 segregationist Dixiecrat presidential bid.

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 a chief spokespersons for their respective political parties holding the majority and the minority in the United States Senate. They are each elected as majority leader and minority leader by the senators of their party caucuses: the Senate Democratic Caucus and the Senate Republican Conference.