In this article we apply the method of quantitative textual analysis known as ‘topic modelling’ to a significant Australian legal text corpus: that of judgments of the High Court of Australia from 1903 to 2015. The High Court of Australia has been a perennial topic for study and analysis. It is the highest court in the Australian judicial hierarchy and the site of many of the most significant contests of legal doctrine and practice in Australian history. We find that the topic models generated by this research enable the development of a range of unique, novel and robust observations of the High Court’s judicial workload and the shifting make-up of its legal subject matter over time. Moreover, this article reveals the feasibility and value of topic modelling as a method for the study of legal texts and practices that might fruitfully complement other methods of legal scholarship.