Oracle bones are pieces of ox scapula and turtle plastron which were used in pyromancy – a form of divination – during the Late Shang period (c. 1250 – c. 1050 BCE) in ancient China. Scapulimancy is the specific term if ox scapulae were used for the divination, plastromancy if turtle plastrons were used. A recent count estimated that there were about 13,000 bones with a total of a little over 130,000 inscriptions in collections in China and some fourteen other countries.

Diviners would submit questions to deities regarding weather, crop planting, the fortunes of members of the royal family, military endeavors, and similar topics. These questions were carved onto the bone or shell in oracle bone script using a sharp tool. Intense heat was then applied with a metal rod until the bone or shell cracked due to thermal expansion. The diviner would then interpret the pattern of cracks and write the prognostication upon the piece as well. Pyromancy with bones continued in China into the Zhou dynasty, but the questions and prognostications were increasingly written with brushes and cinnabar ink, which degraded over time.

Oracle bones bear the earliest known significant corpus of ancient Chinese writing, using an early form of Chinese characters. The inscriptions contain around 5,000 different characters, many of which are still being used today, though the total number of discrete characters is uncertain as some may be different versions of the same character. Specialists have agreed on the form, meanings, and sound of a little more than a quarter of the characters, roughly 1,200 with certainty, but several hundred more remain under discussion; these known characters comprise much of the core vocabulary of modern Chinese. They provide important information on the late Shang period, and scholars have reconstructed the Shang royal genealogy from the cycle of ancestral sacrifices recorded on oracle bones. When they were discovered at the end of the nineteenth century and deciphered in the early twentieth century, these records confirmed the existence of the Shang, whose historicity had been subject to scrutiny at the time by the Doubting Antiquity School.

Oraculology is the discipline for the study of oracle bones and the oracle bone script.

Shang-era oracle bones are thought to have been unearthed occasionally by local farmers since as early as the Sui and Tang dynasties, and perhaps starting as early as the Han dynasty. In Sui and Tang era Anyang, which was at one time the capital of the Shang dynasty, oracle bones were exhumed during burial ceremonies, though grave diggers did not realize what the bones were and generally reinterred them. During the 19th century, villagers in the area who were digging in the fields discovered a number of bones, and used them as dragon bones, following the traditional Chinese medicine practice of grinding up Pleistocene fossils into tonics or poultices. The turtle shell fragments were prescribed for malaria, while the other animal bones were used in powdered form to treat knife wounds.

In 1899, an antiques dealer from Shandong who was searching for Chinese bronzes in the area acquired a number of oracle bones from locals, and later sold several to Wang Yirong, the chancellor of the Imperial Academy in Beijing. Wang was a knowledgeable collector of Chinese bronzes, and is believed to be the first person in modern times to recognize the oracle bones' markings as ancient Chinese writing similar to that on Zhou dynasty bronzes. A legendary tale relates that Wang was sick with malaria, and his scholar friend Liu E was visiting him and helped examine his medicine. They discovered that, before being ground into powder, the bones bore strange glyphs which, having studied the ancient bronze inscriptions, they recognized as ancient writing. Xu Yahui states that, "[n]o one can know how many oracle bones, prior to 1899, were ground up by traditional Chinese pharmacies and disappeared into people's stomachs."

It is not known how Wang and Liu actually came across these specimens, but Wang is credited with being the first to recognize their significance. During the Boxer Rebellion, Wang reluctantly accepted a defense command, and killed himself in 1900 when allied troops entered Beijing. His son later sold the bones to Liu, who published the first book of rubbings of the oracle bone inscriptions in 1903. As news of the oracle bones' discovery spread throughout China and among foreign collectors and scholars the market for the bones exploded, though many collectors sought to keep the location of the bones' source a secret. Although scholars tried to find their source, antique dealers falsely claimed that the bones came from Tangyin in Henan. In 1908, scholar Luo Zhenyu discovered the source of the bones near Anyang and realized that the area was the site of the last Shang dynasty capital.

Decades of uncontrolled digs followed to fuel the antiques trade, and many of these pieces eventually entered collections in Europe, the United States, Canada, and Japan. The first Western collector was the American missionary Frank H. Chalfant (1862–1914). Chalfant called the script "inscriptions upon bone and tortoise shell" in his 1906 book Early Chinese Writing. The Chinese equivalent jiǎgǔwén 甲骨⽂ appeared in the following decades.