The Senate Majority and Minority Leaders are two United States Senators who are elected by the party conferences that hold the majority and the minority respectively. These leaders serve as the chief Senate spokespeople for their parties and manage and schedule the legislative and executive business of the Senate. By rule, the Presiding Officer gives the Majority Leader priority in obtaining recognition to speak on the floor of the Senate.

The Majority Leader customarily serves as the chief representative of his or her party in Senate, and sometimes even in all of Congress if the House of Representatives and thus the office of Speaker of the House is controlled by the opposition party.

Many state senates are organized in the same way as the United States Senate.

Per 19 U.S.C. § 2191(c)(1), an implementing bill for a Fast track negotiating authority (Trade Promotion Authority) trade agreement submitted by the President is introduced (by request) in the House by the majority leader of the House and (by request) in the Senate by the majority leader of the Senate.

In U.S. politics, the majority floor leader is a partisan position in a legislative body.

In the federal Congress, the roles differ slightly in the two houses: the Majority Leader of the House of Representatives and the Majority Leader of the Senate, respectively. In the House of Representatives, which chooses its own presiding officer, the leader of the majority party is elected the Speaker of the United States House of Representatives. The Majority Leader of the House of Representatives is something of a misnomer then, as the title is given to the majority party's second in command. In the United States Senate, its president is ex officio the Vice-President of the United States, and the President pro tempore is a largely ceremonial position, so the majority leader is the actual leader of the majority party.

The role of majority leaders thus differs slightly between the two chambers.

Given the two-party nature of the U.S. system, the majority leader is almost inevitably either a Republican or a Democrat.

Harry Mason Reid (born December 2, 1939) is the senior United States Senator from Nevada, serving since 1987. A member of the Democratic Party, he has been the Senate Majority Leader since January 2007, having previously served as Minority Leader and Minority and Majority Whip.

Previously, Reid was a member of the U.S. House of Representatives, representing Nevada's 1st congressional district, and served in Nevada local and state government as city attorney of Henderson, a state legislator, the 25th Lieutenant Governor, and chairman of the Nevada Gaming Commission.

As Senate Majority Leader and a member of the Church of Jesus Christ of Latter-day Saints, Harry Reid has achieved a more senior elected position in the United States government than any Mormon in history.

Reid was born in Searchlight, Nevada, the third of the four sons of Inez Orena (née Jaynes), a laundress, and Harry Vincent Reid, a miner. His paternal grandmother was an English immigrant from Darlston, Staffordshire. Reid's boyhood home had no indoor toilet, hot water or telephone. Searchlight had no high school, so Reid boarded with relatives 40 miles away in Henderson, Nevada to attend Basic High School where he played football, and was an amateur boxer. While at Basic High he met future Nevada governor Mike O'Callaghan, who was a teacher there. Reid attended Southern Utah University and graduated from Utah State University where he double majored in political science and history. Reid also minored in economics from the Jon M. Huntsman School of Business. He then went to George Washington University Law School earning a J.D. while working for the United States Capitol Police.

Randy Richardville (born August 15, 1959 in Monroe, Michigan) is a Michigan Republican, who is the current state senator for the 17th District, which consists of all of Monroe, southern Washtenaw, and eastern Jackson counties. He took office on January 1, 2007. Previously, he served in the Michigan House of Representatives for the 56th District from 1998 to 2004. This district covered the area of northeast Monroe County, including the city of Monroe.

Richardville was born in Monroe, Michigan. He graduated from Monroe Catholic Central High School— known today as St. Mary Catholic Central— in 1977. He wed Sarah Elford, to whom he is still married, in 1979. He received his Bachelor of Arts degree from Albion College in 1981, and he received his master's degree in management from Aquinas College in 1989.

Richardville has worked for several Fortune 500 and Fortune 1000 companies, including La-Z-Boy, Herman Miller, and North Star Steel. He has involved himself extensively in local and state politics throughout his career. These include working for the WTWR-FM radio station, United Way of Monroe County, the Monroe Chamber of Commerce, American Legislative Exchange Council, Habitat for Humanity, a board member of the Monroe YMCA, Monroe Rotary Club, former board member for the Karmanos Cancer Institution, and many more. He is also a member of the National Rifle Association and Ducks Unlimited. He is currently a member of the Board of Trustees for Monroe Public Schools and the Economic Development Director in southeast Michigan. He has received numerous awards for his work.

Addison Mitchell "Mitch" McConnell, Jr. (born February 20, 1942), a Republican American, is the senior United States Senator from Kentucky and the Minority Leader. He is the longest serving U.S. Senator in Kentucky history.

McConnell was born in Tuscumbia, Alabama to Julia (née Shockley) and Addison Mitchell McConnell.

McConnell was raised in southern Louisville, Kentucky, where he attended the duPont Manual High School, and in 1964 he graduated with honors from the University of Louisville with a B.A. in political science. He was student body president and a member of the Phi Kappa Tau fraternity. McConnell has maintained strong ties to his alma mater, and "remains a rabid fan of its sports teams." He graduated in 1967 from the University of Kentucky College of Law, where he was elected president of the Student Bar Association.

McConnell became a member of the 100th Division (Training), U.S. Army Reserve, in Louisville, Kentucky, during his final semester of law school; and he reported for his six months of active service, primarily for training, in July 1967. After induction at Fort Knox, Kentucky, McConnell was released early from his active-duty military service in August 1967. McConnell received a medical discharge for optic neuritis, which is a common manifestation of multiple sclerosis.