In the late-nineteenth and early twentieth centuries, child actors were ubiquitous in popular theatre forms across the US, Britain, and Australasia. In this first transnational study of child actors, Gillian Arrighi reveals their popularity with the audiences who flocked to see them in dramas, musical comedies, vaudeville, variety, and pantomime, and how they were photographed, written about, and worried about in the print media of the day. Embodying a unique blend of innocence, joy and competence, they appeared alongside the biggest stars of the era and toured vast distances, some of them earning enormous salaries. When anglophone societies were constructing modern childhood through social, labour, and education reforms, it was the popular theatre, Arrighi shows, where audiences went to see transformational ideas about children and childhood brought to life.