This paper offers a critical review of the literature on 21st century knowledge frameworks, with a particular focus on what this means for teachers and teacher educators. The article identifies common themes and knowledge domains in 15 reports, books, and articles that describe the kinds of knowledge that researchers state are integral and important for success in the 21st century. The authors argue that seemingly disparate frameworks converge on three types of knowledge, as necessary for the 21st century: foundational, meta, and humanistic. They argue that the synthesis of these different frameworks suggests that nothing has changed, that this tripartite division between what we know, how we act on that knowledge, and what we value has always been important. This analysis suggests that, though the 21st century is different from previous times, it does not mean that our core roles have changed.