Major General Sir Denzil Macarthur-Onslow CBE, DSO, ED (5 March 1904 – 30 November 1984) was an Australian general.Macarthur-Onslow, the son of grazier Arthur Macarthur-Onslow, enlisted in the Australian Citizens Military Forces in 1924. In 1935, he was appointed captain Ex Reserve of Officers in the 2nd Military District of the Australian Field Artillery; on 31 June 1936 he was appointed a captain in the Royal Australian Artillery.