 Knibbs resigned his directorship of the Institute of Science and Industry in 1926, and lived in retirement until his death of coronary vascular disease at Camberwell, Victoria, a suburb of Melbourne, on 30 March 1929.Knibbs was created a Companion of the Order of St Michael and St George (CMG) in 1911 and was knighted in 1923.He contributed 29 papers to the Royal Society of New South Wales, and several of his monographs, largely on statistical subjects, were published as pamphlets.