Al-Farabi (870-950) - one of the greatest thinkers and encyclopedists of the early Middle Ages. He left a rich scientific heritage, which had a huge impact on the development of science both in the East and in the West. However, not all of al-Farabi's works, especially mathematical ones, have been studied. The book includes all the works of mathematical content known to us, which reveal the work of al-Farabi, enable the reader to get a complete picture of him as a major mathematician of his era. The book is designed for everyone interested in the history of science of the Middle Ages, for scientists, university professors, graduate students, and mathematics students.