This article provides a description of science teacher education policy in Canada and the USA. We focus on qualifications and procedures to obtain an initial teaching license, requirements for license renewal, and trends in our respective countries. In both countries, science teacher education is the responsibility of the province or state, rather than the federal government. Because these countries are composed of many provinces/states, each with its own unique characteristics, we focus on general trends, recognizing that exceptions to these trends exist. Our review indicates that science teacher education in Canada and the USA consists of a highly diverse array of licenses, requirements, and programs. While this variability provides flexibility for programs to meet local needs and to create innovative programs, it also creates the potential for teachers to enter classrooms with insufficient preparation. In both countries, multiple pathways lead to certification, many of which have very few science content or science pedagogy requirements. The science content knowledge required of elementary teachers is of concern in both countries. Secondary science teachers have multiple ways to teach with insufficient preparation in science content and pedagogy. The nature of science is notably absent from most science teacher education state and provincial requirements. Innovative program structures with high requirements for science content and pedagogy exist in both countries. Research is needed that compares program structures and requirements to determine their relative impact on teachers' practices. Additionally, much remains to be done to improve the extent to which existing research influences policy.