The Mosque of Lalla Ghriba (Arabic: مسجد لالة غريبة), also known as the Mosque of El-Korran, is a small mosque in the historic medina of Tlemcen, Algeria. It is located in Derb Es-Sbabet ('Alley of Shoes') in the El Korran neighborhood. The history of this building is not well known.

In Maghrebi popular culture, Lalla Ghriba ('Strange Lady') is a legend and a myth about a woman who was a saint. Her devotions touched the Divine so much that she was gifted with miracles. It is said that she could perform wonders and was buried near this mosque in Tlemcen. According to tradition, she appears at night in the El Korran neighborhood, her white ghost moving between houses, prophesying misfortunes to come for their inhabitants.^[1][2] Another mosque in Fes, Morocco, and a synagogue in Djerba, Tunisia, also bear the name of this mythical figure.^[3][4]

The French researcher Charles Brosselard mentioned the existence of a plaque written in Maghrebi script, composed of 32 lines, describing all the properties and endowments (waqf) such as houses, shops, and books allocated to the mosque to provide services or revenues. He estimated that the plaque was at least two centuries old. Its contents were fully published in 1876 in the Revue africaine.^[5] Abou El Kacem Saâdallah also noted the books preserved by a woman named Fatima Bent Djebour, including a copy of the work of Al-Suyuti and a copy of the work of Ibn al-Jawzi.^[6]