Executive functions (EF) are a set of domain-general cognitive skills that play a key role in regulating learning and behavior. Previous research has shown that executive functioning capacity in early childhood predicts academic achievement in math and literacy. Troublingly, research has also shown that low-income preschoolers tend to lag behind their higher-income peers, not only in academic skills, but also in EF that may support their development of these skills. Preschool science has recently gained attention as another key learning domain where low-income preschoolers also enter kindergarten with low levels of readiness. No existing research has empirically examined the relationship between EF and science outcomes in preschoolers. The current study addresses this gap by testing the ability of EF to predict gains in science as well as math and literacy outcomes in a low-income sample. To assess the extent to which EF are linked to these school readiness outcomes, magnitudes of all predictions were compared. Results indicated that EF significantly predict gains in all domains, including science. Further, EF predicted gains in science to a significantly greater degree than math, and literacy. Implications and future directions including research designs that allow for stronger causal inferences about the potential bidirectional influence of EF and science are discussed. (author abstract)