The Gazi Husrev-Beg Mosque, often referred to as the Beg's Mosque for short, is a mosque in the city of Sarajevo, Bosnia and Herzegovina. It is considered the most important Islamic structure in the country and one of the world's finest examples of Ottoman Architecture. It is located in the Baščaršija neighborhood in Općina Stari Grad.

The mosque was built in 1531 by Gazi Husrev-beg, the provincial governor of Bosnia and a man widely considered Sarajevo's greatest donor who built most of Sarajevo's old city at this time.

The Beg's Mosque was built by a Persian architect, who would later go on to build the Selimiye Mosque in Edirne for the Sultan Selim I. Out of all the Ottoman balkan provinces, Bosnia's population was the quickest to convert to Islam. Due to this, during the height of the Ottoman Empire, many of the most famous examples of Ottoman architecture in the Balkans were built in Bosnia, including Mosques, bridges, libraries, bathhouses, etc. etc. The Gazi Husrev-Beg mosque is a vital part of this period of prosperity and cultural growth.

During the Siege of Sarajevo, Serbian forces purposely targeted many centers of the city's culture, such as museums, libraries, and mosques. As the largest and most well known, the Beg's mosque was an obvious target. Heavily damaged in the war, it was renovated in 1996 with foreign help. Some have accused the renovators (whose money came in large part from Saudi Arabia) of Wahhabizing the mosque. Traditionally the Mosque's insides fit the mold of a Sufi mosque, as seen on the right, but today its appearance is noticeably different. The walls for example are simply white, much of the detail, artistry, and color taken out. The Mosque's teachings however are not Wahhabist in nature, as the sect has gained little foothold in Bosnia. The Mosque to this day remains one of the most popular centers of worship in the city.