The complexity of the innovation process requires leaders to apply diverse and sometimes even contrasting leadership behaviors. This study examined how benevolent and authoritarian leadership types influence idea generation and implementation throughout the innovation process. Drawing on a contingency approach, we proposed that the effectiveness of these types of leadership would vary across different innovation phases. Through a mixed-method approach combining one qualitative study and one experimental study, we found opposing effects of benevolent leadership and authoritarian leadership across innovation phases; i.e., benevolent leadership enhanced idea generation while hindering implementation, whereas authoritarian leadership facilitated idea implementation while suppressing idea generation. Our research findings provide a more nuanced understanding of the leadership-innovation relationship and offer insights for organizations seeking to optimize their innovative outputs by exhibiting leadership contingently during innovation processes.