The concept of policy entrepreneurs has gained increasing attention in studies of policy change, including climate policy and governance. It foregrounds the role of agency in understanding policy change. However, agency of policy entrepreneurs in the policy process is political and conceals the power that shapes how public problems and policies are framed and defined. Thus, policy entrepreneurs should be confronted with the challenge of generating legitimacy, accountability, and justice in their actions and the implementation of their targeted policy change. Drawing on political–philosophical theories of liberal and deliberative democracy as well as environmental and ecological democracy this paper outlines a conceptual framework for critical analytical as well as normative research on strategies and impacts of policy entrepreneurs on democratic governance, primarily in climate policy but also more generally. Empirical research on the strategies and impacts of policy entrepreneurs in recent policymaking on climate change mitigation in the EU and Sweden identifies several deficits related to the democratic principles of legitimacy, accountability, and justice. It is found that policy entrepreneurs from different social spheres use cultural–institutional entrepreneurship to influence beliefs and perceptions on problems and policies. In addition, it is found that public sector policy entrepreneurs use structural entrepreneurship on ideological grounds to change existing power relations in climate governance. In all, the paper brings ideology and politics into research on policy entrepreneurs. It is suggested that not only the strategies used, but also the ideologies of the actors that use them, are decisive for the impacts of policy entrepreneurs, and thus, whether their advocacy will adhere to democratic norms and facilitate or hamper a just transition to climate neutrality and sustainability. The paper ends with proposals on how policy entrepreneurs can act more democratically, how to deal with populist policy entrepreneurs wanting to erode democracy, and conditions for climate justice movements to take responsibility and act in a more entrepreneurial way.