Allen George Debus (August 16, 1926 – March 6, 2009) was an American historian of science, known primarily for his work on the history of chemistry and alchemy.

Paul H. Theerman and Karen Hunger Parshall edited the proceedings, and Debus contributed his autobiography of which this article is a digest.

Allen Debus attended the Evanston public school system, where he showed an early interest in history.

Due to the topical material and dialect songs, he wrote "studying this music gave me an opportunity early on to place past events in their historical context".

In the contextual approach to history, developments should be compared across fields, and this is a feature of the school of Alexandre Koyre, I. Bernard Cohen, and Walter Pagel, the latter two being teachers of Debus.

Debus studied chemical engineering and history, graduating with a major in chemistry in the summer of 1947 from Northwestern University.

In a seminar with W. K. Jordan he presented a paper on the English followers of Paracelsus which received the Bowdoin Prize in the Natural Sciences, the first of two from his years at Harvard.