The fajr prayer, alternatively transliterated as fadjr prayer, and also known as the subh prayer, is one of the five daily mandatory Islamic prayers (salah). Consisting of two rak'a ("bows"), it is performed between the break of dawn and sunrise. It is one of two prayers mentioned by name in the Qur'an. Due to its timing, Islamic belief holds the fajr prayer to be of great importance. During the Islamic holy month of Ramadan, Muslims begin fasting with the fajr prayer.

The fajr prayer consists of two compulsory (fardh) units of prayer (rak'a). In addition, the voluntary sunnah prayer consists of two units of prayer and can be performed before the compulsory prayer.

In fajr, Al-Fatiha and the additional surah are to be read aloud (jahr), as during Maghrib and Isha. It is commonly performed silently when waking up in the morning.

The prayer includes wudu (ritual purification) and salat (ritual prayer).

Fajr replaced salat al-duha as the morning prayer before the five prayers were standardized.

Qur'an 11:114 commands Muhammad to recite at dawn. This verse is taken as foundational for prescribing the times for prayer.

In Qur'an 17:78, dawn is one of the three times that prayer is to be performed. According to Jalal al-Din al-Suyuti's commentary on angels (Al-Haba'ik fi Akhbar al-Mala'ik), this verse describes the witnessing of dawn prayer by the angels of the day and the night.

The most burdensome prayers for the hypocrites are the Isha prayer and the Fajr prayer. If only they knew what (reward) there is in them, they would come to them even if they had to crawl.