His major work was the Biographia dramatica (2 vols., 1782), a set of biographies of dramatists and a descriptive dictionary of their plays. This book, which was an enlargement of David Erskine Baker's Companion to the Playhouse (2 vols., 1764), was re-edited (3 vols.) by Stephen Jones in 1811. The original work by Baker had been based on Gerard Langbaine the Younger's Account of the English Dramatick Poets (1691), Giles Jacob's Poetical Register (1719), Thomas Whincop's List of all the Dramatic Authors (printed with his tragedy of Scanderbeg, 1747) and the manuscripts of Thomas Coxeter. Reed's Notitia dramatica (Addit. MSS. 25390–2, British Museum), supplementary to the Biographia, was never published.
He also revised Robert Dodsley's Collection of Old Plays (12 vols., 1780); and re-edited Samuel Johnson and George Steevens's edition (1773) of Shakespeare. Reed's edition was published in ten volumes (1785), and he gave great assistance to Steevens in his edition (1793). He was Steevens's literary executor, and in 1803 published another edition (21 vols.) based on Steevens's later collections. This, which is known as the first variorum, was re-issued ten years later.
After his death, his library of theatrical literature was catalogued for sale as Bibliotheca Reediana (1807).
- Michael Dobson and Stanley Wells: The Oxford Companion to Shakespeare. OUP 2001. pg. 370.
- John Nichols Literary Anecdotes of the 18th Century (vol. ii., 1812);
- Edward Dowden, Essays, Modern and Elizabethan.
- This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Reed, Isaac". Encyclopædia Britannica (11th ed.). Cambridge University Press.