Son of Daniel de Wet and Susanna Benade, of Ladysmith, Natal, South Africa. Born Ladysmith. He had 3 brothers and 1 sister. He was married on 16 July 1945 to Letitia Viola Benade. He had 2 children: Gale Storm de Wet (born 22 March 1946) and Fredrick O'Connor de Wet (born 7 March 1947). He went to school in Lancaster, Yorkshire, and London. After he passed away the family returned to South Africa in 1956. For his service in WW2, he received the 1939/45 Star, Africa Star, Italy Star and Africa Service Medal
LG Sup 31 July 1945 pg. 3926 - "This officer has displayed the highest standard of efficiency and courage. He has completed a very large number of sorties including many reconnaissances. In April 1945, Lieutenant de Jongh was leading a formation of a strafing reconnaissance. A convoy of motor transport was observed in the Montebelluno area. Despite adverse weather and heavy enemy opposition, this officer led the formation into attack. Twelve of the enemy vehicles were subsequently destroyed and a further three damaged. In air fighting Lieutenant de Jongh has been responsible for the destruction of at least one enemy fighter and has damaged others."