Ada Esther Leverson was a British writer who is known for her friendship with Oscar Wilde and for her work as a witty novelist of the fin-de-siècle.

Adam Ferguson,, also known as Ferguson of Raith, was a Scottish philosopher and historian of the Scottish Enlightenment.

Count Adam Gurowski was a Polish-born author who emigrated to the United States in 1849.

Adam Lindsay Gordon was a British-Australian poet, horseman, police officer and politician. He was the first Australian poet to gain considerable recognition overseas, and according to his contemporary, writer Marcus Clarke, Gordon's work represented "the beginnings of a national school of Australian poetry".

Adam Bernard Mickiewicz was a Polish poet, dramatist, essayist, publicist, translator and political activist. He is regarded as national poet in Poland, Lithuania and Belarus. A principal figure in Polish Romanticism, he is one of Poland's "Three Bards" and is widely regarded as Poland's greatest poet. He is also considered one of the greatest Slavic and European poets and has been dubbed a "Slavic bard". A leading Romantic dramatist, he has been compared in Poland and Europe to Byron and Goethe.

Adam Gottlob Oehlenschläger was a Danish poet and playwright. He introduced romanticism into Danish literature. He wrote the lyrics to the song Der er et yndigt land, which is one of the national anthems of Denmark.

Adam Smith was a Scottish economist and philosopher who was a pioneer in the thinking of political economy and key figure during the Scottish Enlightenment. Seen by some as "The Father of Economics" or "The Father of Capitalism", he wrote two classic works, The Theory of Moral Sentiments (1759) and An Inquiry into the Nature and Causes of the Wealth of Nations (1776). The latter, often abbreviated as The Wealth of Nations, is considered his magnum opus and the first modern work that treats economics as a comprehensive system and as an academic discipline. Smith refuses to explain the distribution of wealth and power in terms of God's will and instead appeals to natural, political, social, economic and technological factors and the interactions between them. Among other economic theories, the work introduced Smith's idea of absolute advantage.

Adelaide Anne Procter was an English poet and philanthropist.

Adelaide Crapsey was an American poet. She was born in Brooklyn, New York, and raised in Rochester, New York. Her parents were the businesswoman Adelaide T. Crapsey and the Episcopal priest Algernon Sidney Crapsey, who moved from New York City to Rochester.

Adelbert von Chamisso was a German poet and botanist, author of Peter Schlemihl, a famous story about a man who sold his shadow. He was commonly known in French as Adelbert de Chamisso de Boncourt, a name referring to the family estate at Boncourt.