William Otto Adolph Julius Danckwerts
William Otto Adolph Julius Danckwerts KC (1853 – 25 April 1914) was a noted British lawyer.
He was educated at the school of the Reverend Robert Templeton in the village of Bedford in the eastern Cape Colony, and then at Gill College. He entered Peterhouse, Cambridge in 1873, graduating with a B.A. in 1877. He studied law at the Inner Temple, was called to the bar in 1878, and became King's Counsel in January 1900.
Although he rose to the top of his profession and earned a high income for his day (£20,000 a year), he never became a judge.
He was the eldest son of Adolph Victor Danckwertz (also known as Viktor Adolf Danckwerts), a German doctor living in Somerset East, South Africa. Adolph Danckwerts was one of four doctors attached to the British German Legion which was recruited for service in the Crimean War. At the end of that war many of these men were resettled in the Cape Colony. 
He married Caroline Mary Lowther. His son Sir Harold Otto Danckwerts (1888–1978) became a lawyer, judge and Privy Counsellor; another son, Rear-Admiral Victor Hilary Danckwerts (1890–1944), was Deputy Commander-in-Chief of the Eastern Fleet and the father of his grandson Peter Victor Danckwerts, chemical engineer and George Cross recipient.
- "Queen's Counsel" The Times (London). Monday, 8 January 1900. (365033), p. 7.
- Jane McSporran. "Great achievers educated at a small East Cape village school". Retrieved 2011-03-18.
- "William Otto DANCKWERTS - From Barnyard to London Bar", an article by Mr. Justice Leslie Blackwell in "Personality", 26 February 1970, cited in Jane McSporran, "Great achievers educated at a small East Cape village".
- "Royal Navy (RN) Officers 1939-1945: D'Aet to Davi". World War II unit histories & officers. Retrieved 2011-03-18.
- (obituary) T. A. Walker, 542; The Times, 27 April 1914, cited in Alumni Cantabrigienses.
- Foster, Joseph (1885). "Danckwerts, William Otto Adolph Julius". Men-at-the-Bar (second ed.). London: Hazell, Watson, and Viney. p. 113.
- "Danckwaerts [Danckwerts], Wilhelmotto Adolph Julius (DNKS873WA)". A Cambridge Alumni Database. University of Cambridge.