Professor Locarnini is a past director of the World Health Organisation (WHO) Regional Reference Laboratory for Hepatitis B and D for the Western Pacific Region (WPRO). He is a inventor on over 20 internationally granted patents. He worked at the Victorian Infectious Diseases Reference Laboratory from 1989, as Director of Laboratory Services from 1990 to 1998 and, in 1993, he oversaw the amalgamation of all the Fairfield Laboratories into the one service of the VIDRL. He subsequently assumed the position of Head, Research & Molecular Development of VIDRL when the laboratory relocated to Melbourne Health in 1998. He is the recipient of numerous awards including the European Association for the Study of Liver Disease (EASL) International Recognition Award in 2010, the Malaysian Liver Foundation's Medal for work on Viral Hepatitis in 2003 and the Gastroenterological Society of Australia (GESA) Distinguished Research Prize in 2013. In 2019 he received the William H. Prusoff HEP DART Lifetime Achievement Award. He is author of 289 peer-reviewed articles, 24 invited editorials and 100 book chapters and reviews and every year delivers numerous invited, and reviews and every year delivers numerous invited, plenary, and named lectures at major international meetings and conferences. He currently has an academic appointment at the University of Melbourne. He is a member of the Scientific Advisory Board of a number of emerging as well as established pharmaceutical and biotechnology companies. In 2017, he co-founded the biotech start-up company CLEAR-B with the Morningside-Newton Investment group in Boston, USA. He is also the Hepatitis Virus Editor for Antiviral Therapy.