Barriers to innovation (e.g., obstacles causing not to innovate) are another critical concept that may affect the implementation of innovation. Innovation in the public sector has traditionally been viewed as something of an oxymoron. Burdened by a slow and stubborn bureaucracy, this traditional view concluded that innovation was essentially anathema to the public sector. More recently, however, careful research has subjected public sector innovation to scrutiny, and concluded that the perception of impervious barriers inhibiting innovative activity in the public sector is a mischaracterization. This chapter explains the differences between the public and private sectors and how this distinction is essential to understand barriers to innovation. Then, it explains the overall barriers to innovation in the public sector. After this explanation, the chapter provides more discussion based on the levels of analysis. Then, it discusses a relatively recent and novel concept: whether barriers to innovations are deterring or revealed. Finally, it provides strategies to policymakers about how to reduce barriers in the public sector.