Medieval Islamic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age (9th–13th centuries), and mostly written in the Arabic language. These developments mostly took place in the Middle East, Central Asia, Al-Andalus, and North Africa, and later in the Far East and India. It closely parallels the genesis of other Islamic sciences in its assimilation of foreign material and the amalgamation of the disparate elements of that material to create a science with Islamic characteristics. These included Greek, Sassanid, and Indian works in particular, which were translated and built upon.

Islamic astronomy played a significant role in the revival of ancient astronomy following the loss of knowledge during the early medieval period, notably with the production of Latin translations of Arabic works during the 12th century.

A significant number of stars in the sky, such as Aldebaran, Altair and Deneb, and astronomical terms such as alidade, azimuth, and nadir, are still referred to by their Arabic names. A large corpus of literature from Islamic astronomy remains today, numbering approximately 10,000 manuscripts scattered throughout the world, many of which have not been read or catalogued. Even so, a reasonably accurate picture of Islamic activity in the field of astronomy can be reconstructed.

The Islamic historian Ahmad Dallal notes that, unlike the Babylonians, Greeks, and Indians, who had developed elaborate systems of mathematical astronomical study, the pre-Islamic Arabs relied upon empirical observations. These were based on the rising and setting of particular stars, and this indigenous constellation tradition was known as Anwā’. The study of Anwā’ was developed after Islamization when Arab astronomers introduced mathematics to their study of the night sky.

The first astronomical texts that were translated into Arabic were of Indian and Persian origin. The most notable was Zij al-Sindhind, a zij produced by Muḥammad ibn Ibrāhīm al-Fazārī and Yaʿqūb ibn Ṭāriq, who translated an 8th-century Indian astronomical work after 770, with the assistance of Indian astronomers who were at the court of caliph Al-Mansur.^{[better source needed]} Zij al-Shah was also based upon Indian astronomical tables, compiled in the Sasanian Empire over a period of two centuries. Fragments of texts during this period show that Arab astronomers adopted the sine function from India in place of the chords of arc used in Greek trigonometry.

Ptolemy’s Almagest (a geocentric spherical Earth cosmic model) was translated at least five times in the late eighth and ninth centuries, which was the main authoritative work that informed the Arabic astronomical tradition.

The rise of Islam, with its obligation to determine the five daily prayer times and the qibla (the direction towards the Kaaba in the Sacred Mosque in Mecca) inspired intellectual progress in astronomy.

The philosopher Al-Farabi (d. 950) described astronomy in terms of mathematics, music, and optics. He showed how astronomy could be used to describe the Earth's motion, and the position and movement of celestial bodies, and separated mathematical astronomy from science, restricting astronomy to describing the position, shape, and size of distant objects. Al-Farabi used the writings of Ptolemy, as described in his Analemma, a way of calculating the Sun's position from any fixed location.