Professor Clarke is Laureate Professor in the School of Botany at The University of Melbourne. She served as President of the International Society for Plant Molecular Biology (1997-1998). She is a Fellow of the Australian Academy of Science, Fellow of the Australian Academy of Technological Sciences and Engineering, Foreign Associate of the National Academy of Sciences (USA) and Foreign Member of the American Academy of Arts and Sciences and a Fellow of Janet Clarke Hall in Melbourne. Professor Clarke was appointed as an inaugural Fellow (2007) of the American Society of Plant Biologists.  She served as Chairman of the CSIRO Board (1991-1996), Lieutenant Governor of Victoria (1997-2000), Ambassador for Biotechnology for Victoria (2001-2004) and has served on many government committees.

Professor Clarke is a Director of Hexima Limited, a company that focuses on agricultural biotechnology. She has also served as a Director on a number of public companies including Alcoa of Australia Limited (1993-96), Woolworths Limited (1994-2007), WMC Limited (1996-2005) and Fisher & Paykel Healthcare Limited (2002-2008). She also serves on various scientific advisory boards including the Australian Research Centre for Urban Ecology (ARCUE) (2004- ).