This thesis answers the question: to what extent is the history of education in Queensland, Australia, a history of secularisation? Through a Foucauldian history of the present, it explores the shifting relationship between Christian and secular ideals in Queensland education from the early twentieth century through to 2017. It focuses on a series of six case studies, each of which examines a moment during which the existing relationship between Christian and secular ideals was challenged. This thesis offers a revised definition of secularisation. This definition holds that secularisation should be understood as (1) historically, culturally, and spatially specific; (2) changing and recursive; (3) situated in power relations; (4) multi-faceted and multi-scalar and (5) existing in the context of multiple modernities. Using this definition, the thesis finds that secularisation has occurred through the history of education in Queensland, despite legislative changes which continue to privilege Christianity. The key data this thesis relies upon are archival sources including letters, reports, and cabinet minutes. Other significant forms of data include newspaper sources, Census data, legislation, and Hansard reports.