The benefit of arts education for cultural engagement, wider academic achievement, and as a contributor to the creative economy is a subject of significant debate. In the present work, we focus on the potential for simple, arts-based improvisation activities to enhance divergent thinking skills and creativity in primary school-age children. In the first experiment, we compare the effect of children taking part in an improvised versus nonimprovised dance class on their subsequent performance on the Instances Task (Wallach & Kogan, 1965) and on a creative “toy” design task. In a second experiment, children took part in verbal and acting improvisation games or in matched control games before completing figural activity 1 of the Torrance Tests of Creative Thinking (TTCT; Torrance, 1974). In both experiments, we found that children who took part in the improvisation interventions showed better divergent thinking and creativity after the intervention. Our findings suggest that simple, arts-based improvisation interventions could have domain-general benefits for creative cognition processes. Furthermore, they indicate one way in which simply making better use of existing arts education provision could provide a cost-effective way to increase creativity-relevant skills in primary schoolchildren. We consider putative mechanisms for the improvisation effects and specify directions for future work.