Alexander Ewan Armstrong (15 June 1916 – 27 April 1985) was an Australian politician. Armstrong was born in Sydney to doctor George Armstrong and Florence Edith Ewan. He attended Scots College and became a grazier, working first on the family's Albury property and then at Winderadeen and Collector. On 10 February 1945, he married Marjorie Alma Goodhew and they had two daughters. He later divorced, and remarried Margaret Rose Cleary in July 1963. He died at Alice Springs in 1985.