John Allen (3 February 1771 – 10 April 1843) was a prominent eighteenth and nineteenth century political and historical writer, and Master of the College of God's Gift in Dulwich (then colloquially called Dulwich College).
John Allen was born at Redfoord in the parish of Colinton near Edinburgh. His father, James Allen, was the owner of the small estate of Redfoord and was a writer to the Signet. When his father became bankrupt his mother's family and his stepfather ensured that he had a good education. In time he was apprenticed to an Edinburgh surgeon by the name of Arnot. Whilst there his companion in instruction was Professor Thomson who would be a lifelong friend.
In 1791 he became M.D. of the University of Edinburgh. After achieving his M.D. he waited for a practice in Edinburgh and whilst doing so lectured on medical topics with students including Francis Horner being attracted. He also translated Cuvier's "Introduction to the Study of the Animal Economy".
He was also known for his promotion of the cause of political reform in Scotland and had a deep knowledge of constitutional history. This led to him being one of the few to whom a plan of the Edinburgh Review was communicated.
In 1801 it became known that Lord Holland required the services of a clever young Scotch medical man to accompany him to Spain. Allen was recommended John Allen took up the position and accompanied Holland's family remaining abroad until 1805. When he returned he spent much of his time at Holland House. For a brief time in 1806 he held an official position as undersecretary to the commissioners for treating with America. In 1808 he again accompanied Lord Holland to Spain and made a study of the history and social characteristics of the Spanish people. His work towards a volume illustrating the different causes that had checked Spain's progress was never finished. However, in April 1810 two articles were published in the Edinburgh Review on Spanish America.