Augustus De Morgan (27 June 1806 – 18 March 1871) was a British mathematician and logician. He formulated De Morgan's laws and introduced the term mathematical induction, making its idea rigorous.

De Morgan is a surname, and may refer to:

Walter Augustus de Havilland (31 August 1872 – 20 May 1968) was an English patent attorney who became professor of Law at Waseda University and was one of the first Westerners to play the game of Go at a high level. He was the father of American film stars Olivia de Havilland and Joan Fontaine.

Baron Frederick Augustus de Zeng (1756 in Dresden, Saxony – 26 April 1838 in Clyde, New York ) was a Hessian mercenary who served in one of the regiments in the British service in the Thirteen Colonies during the American Revolution. He remained after the fighting was over, was naturalized and pursued various businesses.

Sophia Elizabeth De Morgan (1809–1892) was an English spiritualist writer and activist.

Augustus Alfred de Bourbel (1835 – 15 May 1917) was an English cricketer. de Bourbel's batting style is unknown. He was educated at Harrow School.

The Gilded Cage is an oil painting by Evelyn De Morgan, with apparent stylistic influences of spatial representation from Surrealist modes of thought. It was her final work before her death in 1919. It is essentially an allegory for female hypnotic delirium.

General Sir Augustus De Butts KCH (1770 – 28 November 1853) was an officer in the Royal Engineers. De Butts served during the French Revolutionary Wars, fighting in the Siege of Toulon, the Siege of Bastia, and the Siege of Calvi.