Luke Lea the Younger (April 12, 1879 – November 18, 1945) was a Democratic United States Senator from Tennessee from 1911 to 1917.

Lea was the great-grandson of an earlier Luke Lea (1783-1851) who was a two-term Congressman from Tennessee in the 1830s and ardent supporter of Andrew Jackson.

The younger Lea attended public schools and then the University of the South in Sewanee, Tennessee, graduating from that institution in 1899. He then attended the Columbia University law school in New York City, completing his studies at that prestigious institution in 1903 and being admitted to the bar the same year, beginning practice in Nashville.

Lea was the founder of the Nashville Tennessean and its first editor and publisher. He was elected to the Senate by the Tennessee General Assembly in 1911. He was an enthusiastic supporter of most of the progressive policies of Democratic President Woodrow Wilson, a fellow native of the South and only the second member of the Democratic Party to have been elected President since the end of the Civil War until that point, whose service began in 1913 following his election in 1912. During the 63rd Congress, Lea was chairman of the Senate Committee on the Library (of Congress).

During Lea's term, the Seventeenth Amendment changed the method of election of Senators from that of election by the state legislatures to a direct popular vote. Lea contended for the 1916 Democratic nomination for the seat but was defeated by Kenneth McKellar, a colleague of Memphis political "boss" E. H. Crump, who went on to serve six terms as Tennessee's longest-serving senator.

Shortly after the expiry of Lea's Senate term the U.S. entered World War I. Lea volunteered and was commissioned as an artillery officer, serving in Europe, where he was promoted to the rank of colonel. After the close of the war, he returned to Nashville and resumed operation of his newspaper. In 1929 Lea was nominated for appointment by governor of Tennessee Henry H. Horton to Tennessee's other Senate seat, vacated by the death of Senator Lawrence D. Tyson. Lea, however, declined this appointment, choosing instead to enter the banking and real estate businesses in an era when the speculative nature of the practices in those industries was about to contribute to the Great Depression. Many accusations were subsequently made about Lea and his friends, and he became the subject of much rumour and inneuendo, but was never convicted of any wrongdoing. The book World Enough and Time by poet and novelist Robert Penn Warren is said to be a roman à clef about the events of this era in the Nashville area. Lea died in Nashville and is buried in that city's Mount Olivet Cemetary, the final resting place of several Tennessee governors and senators.

Lea Heights in Nashville's Percy Warner Park, a place offering an excellent view of the downtown Nashville skyline, is named in his honor.

This article incorporates facts obtained from the public domain Biographical Directory of the United States Congress.