Copyright © 2019 The Society of Legal Scholars. The future is likely to see an increase in the public-sector use of automated decision-making systems which employ machine learning techniques. However, there is no clear understanding of how English administrative law will apply to this kind of decision-making. This paper seeks to address the problem by bringing together administrative law, data protection law, and a technical understanding of automated decision-making systems in order to identify some of the questions to ask and factors to consider when reviewing the use of these systems. Due to the relative novelty of automated decision-making in the public sector, this kind of study has not yet been undertaken elsewhere. As a result, this paper provides a starting point for judges, lawyers, and legal academics who wish to understand how to legally assess or review automated decision-making systems and identifies areas where further research is required.