Mathieu is Professor of Communication in the University of Canberra‚ News and Media Research Centre and Honorary Associate Professor of Sociology at the Australian National University. Mathieu co-founded the Australian National University‚ Virtual Observatory for the Study of Online networks, a world leader in big data analytics and computational social science. He has also initiated multidisciplinary collaborations at the University of Canberra. With Faculty of Education colleagues, he is designing information literacy resources which ACT primary and secondary schools are using to address epistemic pollution. Mathieu has played a key role in developing the analysis and recognition of digital commons such as free and open source software and Wikipedia, by founding and editing the peer-reviewed Journal of Peer Production (2011-2021), by editing the Handbook of Peer Production (Wiley, 2021), and by founding an international think tank, the Digital Commons Policy Council, in 2021. Mathieu's research has been published in peer-reviewed journals such as Social Networks, Information, Communication & Society, New Media and Society, the International Journal of Communication, and Organization Studies, amongst others.