The Great Mosque of Herat (Pashto: د هرات لوی جومات ; Dari: مسجد جامع هرات, romanized: Masjid-i Jāmi'-i Herāt) or "Jami Masjid of Herat", is a mosque in the city of Herat, in the Herat Province of north-western Afghanistan. It was built by the Ghurids, under the rule of Sultan Ghiyath al-Din Muhammad Ghori, who laid its foundation in 1200 CE. Later, it was extended several times as Herat changed rulers down the centuries from the Kartids, Timurids, Mughals and then the Uzbeks, all of whom supported the mosque. The fundamental structure of the mosque from the Ghurid period has been preserved, but parts have been added and modified. The Friday mosque in Herat was given its present appearance during the 20th century.

Apart from numerous small neighborhood mosques for daily prayer, most communities in the Islamic world have a larger mosque, a congregational mosque for Friday services with a sermon. The Jami Masjid of Herat was not always the largest mosque in Herat; a much larger complex, the Mosque and Madressa of Gawhar Shad, also built by the Timurids, was located in the northern part of the city. However, those architectural monuments were dynamited by officers of the British Indian Army in 1885, to prevent its use as a fortress if a Russian army tried to invade India.