Examining ideas of democracy and professionalisation, this book explores how these concepts developed in the twentieth-century art museum between the 1930s and the 1950s, with particular attention to debates across Anglo–American and European institutions. Drawing on research from national and regional art institutions in Leeds and London, it shows that efforts to democratise the museum were gradual and uneven. These initiatives were often framed through a rhetoric of modernisation that was often in conflict with the ways galleries actually sought to open their doors to broader publics. Through a nuanced analysis of mid-twentieth-century art museum discourses, practices, environments, and systems, the book reveals how processes of democratisation reshaped institutions in complex and often contradictory ways. The book will be of interest to scholars in art history, museum studies, cultural history, and museology.