Mosque of Omar, Masjid Umar, Masjid-e-Umar, Al-Omari Mosque or Mosque of Omar ibn al-Khattab is a name given to many mosques, usually referring to Omar, a companion of Muhammad and Caliph (579-644) recognized by Sunni Muslims in the succession to Muhammad.
Masjid is the Arabic word for a place of worship, commonly translated as mosque in English.
Notable ones include (alphabetically, by city):