David Pinski was a Yiddish language writer, probably best known as a playwright. At a time when Eastern Europe was only beginning to experience the industrial revolution, Pinski was the first to introduce to its stage a drama about urban Jewish workers; a dramatist of ideas, he was notable also for writing about human sexuality with a frankness previously unknown to Yiddish literature. He was also notable among early Yiddish playwrights in having stronger connections to German language literary traditions than Russian.

David Ricardo was a British political economist, politician, and member of the Parliament of Great Britain and Ireland. He is recognized as one of the most influential classical economists, alongside figures such as Thomas Malthus, Adam Smith and James Mill.

David Starr Jordan was the founding president of Stanford University, serving from 1891 to 1913. He was an ichthyologist during his research career. Prior to serving as president of Stanford University, he had served as president of Indiana University from 1884 to 1891.

David Friedrich Strauss was a German liberal Protestant theologian and writer, who influenced Christian Europe with his portrayal of the "historical Jesus", whose divine nature he denied. His work was connected to the Tübingen School, which revolutionized study of the New Testament, early Christianity, and ancient religions. Strauss was a pioneer in the historical investigation of Jesus.

David Urquhart Jr. was a Scottish diplomat, writer and politician, serving as a Member of Parliament from 1847 to 1852. He also was an early promoter of the Turkish bath in the United Kingdom.

Gunard Hjertstedt, better known by pen name Day Keene, was an American novelist, short story writer and radio and television scriptwriter. Keene wrote over 50 novels and was the head writer for radio soap operas Little Orphan Annie and Kitty Keene, Inc. Several of his novels were adapted into movies, including Joy House and Chautauqua, released as The Trouble with Girls.

Deborah Alcock was a late-Victorian author of historical fiction focused on religious, evangelical themes.

Demosthenes was a Greek statesman and orator in ancient Athens. His orations constitute a significant expression of contemporary Athenian intellectual prowess and provide insight into the politics and culture of ancient Greece during the 4th century BC. Demosthenes learned rhetoric by studying the speeches of previous great orators. He delivered his first judicial speeches at the age of 20, in which he successfully argued that he should gain from his guardians what was left of his inheritance. For a time, Demosthenes made his living as a professional speechwriter (logographer) and a lawyer, writing speeches for use in private legal suits.

Denis Diderot was a French philosopher, art critic, and writer, best known for serving as co-founder, chief editor, and contributor to the Encyclopédie along with Jean le Rond d'Alembert. He was a prominent figure during the Age of Enlightenment.

Dennis Yeats Wheatley was a British writer whose prolific output of thrillers and occult novels made him one of the world's best-selling authors from the 1930s through the 1960s. His Gregory Sallust series was one of the main inspirations for Ian Fleming's James Bond stories.