Disagreement exists about how to best spark young children's motivation to learn natural science. Both curiosity and wonder are considered important motivational factors for learning during early childhood (0-8 years). This systematic literature review explores research about scientific curiosity and wonder in early childhood education and care published from 2010-2020. The review outlines the population of interest (participants in the study, age of children, study location), methodological trends, and how curiosity and/or wonder are included in the research. The search yielded 300 peer-reviewed articles, of which 33 were included for analysis based on eligibility criteria. The main results showed that: (a) the term "curiosity" was more commonly used than the term "wonder," (b) few studies elaborated on their understanding of the two terms beyond them being naturally present in children, and (c) curiosity and/or wonder were emphasized as means to learn natural science or considered as stimulated by it, although few studies discussed how children's curiosity and wonder can be observed and nurtured. With a better understanding of what defines the terms curiosity and wonder and how to foster these qualities in early childhood education and care, we can learn to better support children's intrinsic motivation for science learning.