First published in 1521, "The Art of War" is a treatise by the Italian Renaissance political philosopher Niccolò Machiavelli that echoes the Treaty of the Chinese philosopher Sun Tzu.

In this, the least known of his works, Machiavelli gives straightforward advice on organising and conducting military operations. "The Art of War"'s clear, and concise style is diametrically opposed to that of "The Prince." The book is wholly practical and considers contrasting arguments. Its format is that of a conversation between a military expert and interested citizens. Although the expert, Fabrizio, is obviously Machiavelli himself, the format provides at least an arguable degree of separation between Machiavelli and his advice.