Sir William Henry Lionel Cox (c. 1844 – November 1921) was a British lawyer and judge. He served as Chief Justice of the Straits Settlements in the late 19th and early 20th centuries.^[1]

Cox was born in about 1844 in Mauritius, the son of physician George B. Cox, and was educated at the Royal College,^[2] Mauritius and the University of London. He was called to the Bar at the Middle Temple in 1866.^[3]

In 1880, Cox was appointed Substitute Procureur and Advocate General of Mauritius, and in August of that year Puisne Judge of the Supreme Court. In August 1886 he became Procureur and Advocate-General, which position he held until his elevation on 8 November 1893 to Chief Justice of the Straits Settlements

He was knighted in 1896.^[4]

In 1896, Cox denied an application for a writ of habeas corpus to free Jose Rizal who was being transported on a Spanish warship back to the Philippines when the ship stopped in Singapore.^[5]

Cox married first, Lucy Pelte, of Mauritius, who died in 1900; and, secondly, in 1903 in Yokohama, Elizabeth Cushing Pughe, daughter of Lewis Pughe of Scranton, Pennsylvania.^[6]

Cox retired to England in 1906. In 1915, he was living in Guernsey and was almost blind.^[7]

Cox died in Guernsey in 1921. A special service was held in the Singapore Supreme Court to remember him.^[8]

Lionel Cox Street in Curepipe, Mauritius and Cox Terrace in Fort Canning Park, Singapore are named after Cox.^[9]