British civil engineer who proposed and designed the first Aswān (Assuan) Dam and executed major irrigation projects in South Africa and Turkey.

In 1872 he entered the Indian Public Works Department and in 1883 began work in the Egyptian Public Works Department. While serving as director general of reservoirs for Egypt, he completed studies and plans on the Aswān Dam, which was completed in 1902.

Willcocks retired from his Egyptian post in 1897 and four years later went to South Africa to plan irrigation systems for the arid regions. Part of his scheme was implemented and brought him a knighthood. He became head of irrigation for the Turkish government and in 1911 proposed a plan to bring water to the area of ancient Chaldea, now southern Iraq. As a result, the Hindīyah Barrage was built on the Euphrates River, near the site of ancient Babylon, and 3,500,000 acres were brought under irrigation.