Professor Pettit is the inaugural Chair of Urban Science at the University of New South Wales (2015), being previously at the University Melbourne (20011-2015). The State Government of Victoria, (2004-2011) and RMIT University (2002-2004). He is responsible for the Digital Cities course at UNSW.
He previously developed the Urban Informatics course at the University of Melbourne and was the lead author on the ESRI online virtual campus course in GIS and Planning which attracted more than 3,000 students between 2000 and 2010.
His educational background has been focussed specifically on the fields of spatial planning and GIS at the undergraduate and postgraduate level. Professor Pettit is closely involved with a number of professional organisations. He is a member of the Surveying and Spatial Sciences Institute (SSSI) and the Planning Institute of Australia (PIA).