In 1929 Butler married Margaret Lois Hope, a botanist and Cambridge graduate, at Haddington, East Lothian. They had three children, all successful in their respective fields of biological
and medical sciences. From 1949 to 1977 the Butler’s lived in Rickmansworth in a house then known as Nightingale Corner, which had previously belonged to Hubert J. Foss, first Musical Editor (1923–1941) for Oxford University Press. Like the Fosses, the Butlers often entertained guests there.
J. A. V. died on 16 July 1977