Oldest Mosques in the World

 Al-Aqsa Mosque, Jerusalem
First Built: 705

The designation of the oldest mosque in the world requires careful use of definitions, and must be divided into two parts, the oldest in the sense of oldest surviving building, and the oldest in the sense of oldest mosque congregation. Even here, there is the distinction between old mosque buildings that have been in continuous use as mosques, and those that have been converted to other purposes; and between buildings that have been in continuous use as mosques and those that were shuttered for many decades. In terms of congregations, they are distinguished between early established congregations that have been in continuous existence, and early congregations that ceased to exist (wikipedia).

Al-Masjid al-Nabawi, Saudi Arabia
First Built: 622

 Al-Zaytuna Mosque, Tunisia
First Built: 709

 Great Mosque of Kufa, Iraq
First Built: 639

 Imam Hussain Mosque, Iraq
First Built: 680

 Jawatha Mosque, Saudi Arabia
First Built: 629

 Masjid al-Haram, Saudi Arabia
First Built: 638

 Masjid al-Qiblatain, Saudi Arabia
First Built: 623

 Mosque of Uqba, Tunisia
First Built: 670

  Quba Mosque, Saudi Arabia
First Built: 622