Graduating from the University of Melbourne in 1930 with a Bachelor of Agricultural Science Geoffrey Dean Loftus-Hills found work with the Victorian Department of Agriculture. In 1934 -1935 he took a research tour of the United Kingdom, United States of America and Europe visiting institutions such as the UK's National Institute for Research in Dairying.

In 1940 Geoffrey Dean Loftus-Hills became an employee of the Commonwealth Scientific and Industrial Research Organisation (CSIRO), then known as the Council for Scientific and Industrial Research (CSIR). By 1947 he had been promoted to Chief of the Dairy Research Section, Division of Industrial Chemistry at CSIRO a post he retained until 1962. In 1962 the Dairy Research Section became the Division of Dairy Research. Geoffrey Dean Loftus-Hills continued on as Chief of this new division until his retirement in 1971.

In addition to these roles Geoffrey Dean Loftus-Hills was also the President of the International Dairy Federation Commission B - Technology and Engineering, was director of the 18th International Dairy Congress in 1970 and was editor-in-chief of the Australian Journal of Dairy Technology from 1952 to 1968.

In 1976 the Dairy Industry Association of Australia introduced the Loftus-Hills award in his honour. It is awarded annually to a person who has published an article or articles which make a significant contribution to dairy science or technology.