Wādī Ghalīlah, Valley system in Ras Al Khaimah, United Arab Emirates.

Wadi Ghalilah is a dry river valley in the Emirate of Ras Al Khaimah, formed where the Wadi Litibah and Wadi Barut meet. At that confluence stands the Wadi Ghalilah Dam, 420 metres wide and 6 metres high, built in 2001. From the dam the wadi runs east to west, dropping 140 metres over 10 km to its mouth on the Persian Gulf.

The wadi's name and those of its tributaries Wadi Litibah and Wadi Barut were recorded between 1950 and 1960 by the British Arabist and cartographer Julian F. Walker during border work between the Trucial States, later completed by the UK Ministry of Defence on 1:100,000 maps published in 1971. Earlier, John Gordon Lorimer (1870–1914) referred to Ghalilah in his encyclopedic work on the tribes of the Musandam Peninsula. The area was historically inhabited by the semi-nomadic Shihuh, notably the Bani Shatair and Bani Hadiyah sections.

The wadi and its tributaries were mapped between 1950 and 1960 by the British diplomat and cartographer Julian F. Walker during border work between the Trucial States. The semi-nomadic Shihuh tribe, section of Bani Shatair, lived in the tribal areas of Mahabib, Rahabah, Bani Sa'ad and Hammad, while Bani Hadiyah occupied Ahl Sayh. The name Ghalilah is also used for the whole drainage basin and for postal purposes, so tributaries such as Wadi Litibah and Wadi Barut are often wrongly called Wadi Ghalilah.

This valley is best explored with a sturdy vehicle, as the tracks are rough and can become impassable during rain. It helps to check weather forecasts before visiting and bring plenty of water, since shade is limited in the area.

The Wadi Ghalilah Dam, built in 2001 at the confluence of the Wadi Litibah and Wadi Barut, is 420 metres wide and 6 metres high. Its main purpose is to recharge groundwater and reduce flood damage. The wadi's drainage sub-basin covers 76.32 km², and the name is often wrongly applied to its tributaries, including Wadi Halhal and Wadi Khabb.