The innovativeness of individual employees is a vital source of competitive advantage of firms, contributing to societal development. Therefore, the aim of this multilevel study was to examine how entrepreneurial firm owners' authentic leadership relates to their employees' innovative behaviour. Our conceptual model postulates that the relationship between business owners' authentic leadership (as perceived by their employees) and their employees' innovative behaviour is mediated by employees' personal initiative and their work engagement. Hypotheses derived from this model were tested on data collected from 711 employees working in 85 small firms from three European countries: the Netherlands, Poland, and Spain. The results of the multilevel modelling confirmed our model, showing that when business owners are perceived as more authentic leaders, their employees show higher personal initiative and are more engaged at work and, in turn, identify more innovative solutions to be implemented in the organization. A cross-national difference was observed: employees from Spain (in comparison to Dutch and Polish employees) reported engaging less frequently in innovative behaviour. These research findings suggest that the innovative behaviour of employees can be boosted through leadership training, improving the quality of relationships between leaders and subordinates, and strengthening employees' personal initiative and work engagement.