Marcello Costa (born 9 January 1940) is an Italian-born Australian medical researcher, academic, and public health advocate.
He specializes in the structure and functions of the enteric nervous system.
He taught in Turin, Melbourne, and Helsinki before moving to Adelaide in 1975 where he was a foundation lecturer at the Flinders Medical School, building the new discipline of neuroscience at the college.
He has been at Flinders University since, where he is the Matthew Flinders Distinguished Professor of Neurophysiology in the Department of Physiology.
He co-founded the Australian Neuroscience Society, the South Australian Neuroscience Institute (SANI) and the Friends of Science in Medicine (FSM).
He was awarded the Australian Centenary Medal and the inaugural Lifetime Achievement Award by the Federation of Neurogastroenterology and Motility Societies.