He was born at Kibworth Harcourt, Leicestershire, England, son of John Aikin, Unitarian divine, and received his elementary education at the Nonconformist academy at Warrington, where his father was a tutor.

However, he concerned himself more with the advocacy of liberty of conscience than with his professional duties, and he began at an early period to devote himself to literary pursuits, to which his contributions were incessant.

In conjunction with his sister, Anna Laetitia Barbauld, he published a popular series of volumes entitled Evenings at Home (6 vols, 1792–1795), for elementary family reading, which were translated into almost every European language.

[1] In 1798 Aikin retired altogether from medicine and devoted himself to literary undertakings such as his General Biography (10 vols, 1799–1815).

His other work included Biographical Memoirs of Medicine in Great Britain (1780), The Arts of Life... described in a series of letters.