Wadi al-Thumamah () is a wadi (valley) located approximately 90 kilometers northeast of Riyadh in Riyadh Governorate, Saudi Arabia. It descends from the Al-Armah mountains and passes through Ghilanah village and ends at Rawdat Khuraim in Ramah Governorate of Riyadh Province. The valley is 60 km long and has an average slope of 3 min/km. It is named after Thumam (Arabic: çÃÂëàçà), the Arabic word for desert bunchgrass.