The History of the Peloponnesian War is a historical account of the Peloponnesian War (431–404 BC), which was fought between the Peloponnesian League (led by Sparta) and the Delian League (led by Athens). It was written by Thucydides, an Athenian historian who also served as an Athenian general during the war. His account of the conflict is widely considered to be a classic and regarded as one of the earliest scholarly works of history. The History is divided into eight books.

Analyses of the History generally occur in one of two camps. On the one hand, some scholars such as J. B. Bury view the work as an objective and scientific piece of history. The judgment of Bury reflects this traditional interpretation of the History as "severe in its detachment, written from a purely intellectual point of view, unencumbered with platitudes and moral judgments, cold and critical."

On the other hand, in keeping with more recent interpretations that are associated with reader-response criticism, the History can be read as a piece of literature rather than an objective record of the historical events. This view is embodied in the words of W. R. Connor, who describes Thucydides as "an artist who responds to, selects and skillfully arranges his material, and develops its symbolic and emotional potential."