The 21st century is distinguished for its new innovations and dependency on technology in all parts of libraries, while managers and leaders are two inseparable components of every developing library. This paper contest on who best fits the helms of affairs of libraries in the 21st century between managers and leaders. It explains that managers are always designed around current realities by serving as instruments of planning, controlling and measuring, while leaders are adaptive, flexible, responsive and adopt evolutionary approaches to drive changes. Some leadership patterns, such as purposeful leadership, visionary, transformational, transactional, autocratic, distributed, laissez-faire and servant are suggested as for librarians to adopt to position libraries for reckoning. It concludes that library managers need to elevate their games to become leaders because libraries will be limited and stagnated if management is prioritized over leadership. One of the recommendations of this paper is that library schools and other library-related institutions should be teaching leadership training to students.