Douglas was the Chairman of Amalgamated Dairies Ltd and a number of other private companies. He was a former Chairman of Sanford Ltd, Deputy Chairman of Fernz Corporation Ltd (now Nufarm Ltd) and a former Chairman of Cambridge Clothing Co Ltd and Refrigeration Engineering Ltd. He was a former trustee of various charitable organisations, including those in medical research and education. He was awarded an Honorary Doctor of Law by the University of Auckland and was an Honorary Fellow of the Royal New Zealand College of General Practitioners. Douglas Goodfellow was on the Board of the Auckland Medical Research Foundation from 1978 – 2008.