Leitch Ritchie (1800–1865) was a Scottish novelist and journalist. He was born at Greenock and worked as a clerk in Glasgow, but about 1820 adopted literature as his profession.

Count Lev Nikolayevich Tolstoy, usually referred to in English as Leo Tolstoy, was a Russian writer regarded as one of the greatest authors of all time. He received nominations for the Nobel Prize in Literature every year from 1902 to 1906 and for the Nobel Peace Prize in 1901, 1902, and 1909.

Leo Wiener (1862–1939) was an American historian, linguist, author and translator.

Lev Davidovich Bronstein, better known as Leon Trotsky, was a Russian revolutionary, Soviet politician, and political theorist. Along with Vladimir Lenin, he was a central figure in the October Revolution and the establishment of the Soviet Union. Ideologically a Marxist, Trotsky's writings and thought inspired a school of the ideology known as Trotskyism.

Leona Dalrymple was an early 20th century American writer of novels, short stories, and plays.

Leonard Bloomfield was an American linguist who led the development of structural linguistics in the United States during the 1930s and the 1940s. He is considered to be the father of American distributionalism. His influential textbook Language, published in 1933, presented a comprehensive description of American structural linguistics. He made significant contributions to Indo-European historical linguistics, the description of Austronesian languages, and description of languages of the Algonquian family.

Leonard Merrick was an English novelist. Although largely forgotten today, he was widely admired by his peers; J. M. Barrie called Merrick the "novelist's novelist."

Leonard Sidney Woolf was a British political theorist, author, publisher, and civil servant. He was married to author Virginia Woolf. As a member of the Labour Party and the Fabian Society, Woolf was an avid publisher of his own work and his wife's novels. A writer himself, Woolf created nineteen individual works and wrote six autobiographies. Leonard and Virginia did not have any children.

Leonard Woolsey Bacon was an American clergyman, born in New Haven, Connecticut. He was a social commentator and a prolific author on religious, social, and historical matters. In social, political, and religious issues of his times, he often broke with the traditions of his countrymen, sometimes causing "great sensation."

Leonid Nikolaievich Andreyev was a Russian playwright, novelist and short-story writer, who is considered to be a father of Expressionism in Russian literature. He is regarded as one of the most talented and prolific representatives of the Silver Age literary period. Andreyev's style combines the elements of realist, naturalist, and symbolist schools in literature. Of his 25 plays, his 1915 play He Who Gets Slapped is regarded as his finest achievement.