Simon Forman (31 December 1552 – 5 or 12 September 1611) was an Elizabethan astrologer, occultist and herbalist active in London during the reigns of Queen Elizabeth I and James I of England.

Astrologers continued to revere him, while writers from Ben Jonson to Nathaniel Hawthorne came to characterize him as either a fool or an evil magician in league with the Devil.

In the 1590s Forman began to develop a more serious interest in the occult,[5] eventually setting up a thriving practice as an astrologer physician, documented in his detailed casebooks of his clients' questions about illness, pregnancy, stolen goods, career opportunities and marriage prospects.

[7]Five years after his death he was implicated in the murder of Thomas Overbury when two of his patients, Lady Frances Howard and Mrs Anne Turner, were found guilty of the crime.

During the testimony of Howard's trial, lawyers hurled accusations at Forman, saying he had given Lady Essex the potion with which she plotted to kill Overbury.

During the trial he was described by Sir Edward Coke, Lord Chief Justice of the King's Bench, as the "Devil Forman"; the result being that his reputation was severely tarnished.

Forman's papers have proven to be a treasure trove of rare, odd, unusual data on one of the most studied periods of cultural history.

They include autobiographies, guides to astrology, plague tracts, alchemical commonplace books and notes on biblical and historical subjects.

Forman left behind a large body of manuscripts dealing with his patients and with all the subjects that interested him, from astronomy and astrology to medicine, mathematics and magic.

L. Rowse is one prominent example,[a] and others have followed his lead—have exploited Forman's manuscripts for the manifold lights they throw on the less-exposed private lives of Elizabethan and Jacobean men and women.

Sixty-four volumes of his manuscripts were collected by Elias Ashmole in the seventeenth century, and are now held in the Bodleian Library, Oxford.