This article systematically reviews empirical studies involving scientific literacy published in peer-reviewed journals, focusing on the construction of scientific literacy in formal education worldwide, the suggested ways of adopting scientific literacy in the early years, and the current practices and future possibilities for scientific literacy research in the early years. From searching three databases between 2001 and 2022, including EBSCOhost (Education), ERIC, and Web of Science, as well as additional sources, 79 articles out of 857 were selected for final analysis. Most of them covered primary, secondary and higher education and were dominated by quantitative methods. The selected studies mainly investigated scientific literacy topics related to the effect of programs/projects, assessing the scientific literacy level, teaching-learning and classroom practices, and teachers' views. Some gaps were identified in line with adopting scientific literacy in the early years: less of a focus on early years, play-based activities, intentionality and cultural context; a missing link regarding continuity from one level to another; an underrepresentation of theoretical aspects and children's perspectives; and less concentration on addressing policy, exploring parental views, and identifying factors for making scientific literacy sustainable. This review recommends conducting studies in these areas to explore scientific literacy in the early years.