Ranikot Fort (Sindhi: ) is a historical fort near Sann, Jamshoro District, Sindh, Pakistan. Ranikot Fort is also known as The Great Wall of Sindh and is believed to be the world’s largest fort with a circumference of approximately 26 kilometers (16 mi). Since 1993, it has been on the tentative list of UNESCO World Heritage Sites.

The original purpose and architects of Ranikot Fort are unknown. Some archaeologists attribute it to Arabs, or possibly built by a Persian noble under the Abbasids by Imran Bin Musa Barmaki who was the Governor of Sindh in 836. Others have suggested a much earlier period of construction attributing to at times the Sassanians Persians and at times to the Greeks. Even though a prehistoric site of Amri is nearby, there is no trace of any old city inside the fort and the present structure has little evidence of prehistoric origins.