The Art of War is an ancient Chinese military treatise dating from the Late Spring and Autumn Period (roughly 5th century BC). The work, which is attributed to the ancient Chinese military strategist Sun Tzu ("Master Sun", also spelled Sunzi), is composed of 13 chapters. Each one is devoted to an aspect of warfare and how it applies to military strategy and tactics. For almost 1,500 years it was the lead text in an anthology that would be formalised as the Seven Military Classics by Emperor Shenzong of Song in 1080. The Art of War remains the most influential strategy text in East Asian warfare and has influenced both Eastern and Western military thinking, business tactics, legal strategy and beyond.

The book contained a detailed explanation and analysis of the Chinese military, from weapons and strategy to rank and discipline. Sun Tzu also stressed the importance of intelligence operatives and espionage to the war effort. Because Sun Tzu has long been considered to be one of history's finest military tacticians and analysts, his teachings and strategies formed the basis of advanced military training for centuries to come.

The book was translated into French and published in 1772 (re-published in 1782) by the French Jesuit Jean Joseph Marie Amiot. A partial translation into English was attempted by British officer Everard Ferguson Calthrop in 1905 under the title The Book of War. The first annotated English translation was completed and published by Lionel Giles in 1910. Military and political leaders such as the Chinese communist revolutionary Mao Zedong, Japanese daimyō Takeda Shingen, Vietnamese general Vo Nguyen Giap, and American military general Norman Schwarzkopf Jr. have drawn inspiration from the book.