Leaders are responsible for empowering and driving employees to succeed in challenging times or changes and, ultimately, achieve the best results. One of the biggest dilemmas in today’s leaders’ agenda is to understand how to manage a diverse multigenerational workforce in which millennials represent a predominant group by far, being completely different from previous generations due to the technology impact. The aim of the paper is to identify which leadership style and behavior affects most positively millennial job satisfaction in a multinational environment, and to understand the differences between millennials and non-millennials. The Multifactor Leadership Questionnaire, known as the MLQ, was answered by 167 representative employees from various multinational corporations, 125 of whom are millennials. Based on the results, transformational style is strongly correlated with and positively affected by millennial job satisfaction. Moreover, transformational style is a significant predictor of increased millennial satisfaction, and more specifically, idealized attributes and intellectual stimulation are behaviors that have been validated to increase it. On the other hand, individual consideration has been proven to have a productive effect by increasing non-millennial job satisfaction. According to the findings, millennial workforce leaders need to move towards a more transformational style, based on more idealized attributes and an intellectual stimulation approach, if they want to increase their satisfaction and avoid unwanted attrition. Basically, millennials are searching for leaders who trust and embrace innovation, creativity, critical thinking and, most importantly, leaders who also question the status quo.