This systematic review and meta-analysis synthesised evidence on teaching problem-solving skills to children in early childhood education and care settings (ECEC) in the domain of science, technology, engineering and mathematics (STEM). Given the foundational nature of early cognitive development and the growing emphasis on STEM competencies, this review addresses a critical gap by evaluating the effectiveness of intervention strategies in ECEC settings. A total of 13,030 abstracts were screened across PsycInfo, ERIC, Education Source and Child Development and Adolescent Studies. Nineteen studies met inclusion criteria for the systematic review, and 10 of these (comprising 1355 children) were eligible for meta-analysis. Problem-solving skills focused interventions in STEM were associated with increased problem-solving skills for children attending ECEC settings. Specifically, multivariate meta-analyses for the pooled effects revealed moderately strong effects, r = 0.40. Studies employing an experimental design with random group assignment and author-created outcome measures showed relatively moderate effect sizes compared to other studies, all falling within a moderately strong range depending on outcome measure types. Analysis of the role of potential moderators and implications for practice were also discussed. This review underscores the importance of intentionally integrating STEM problem-solving opportunities into ECEC settings. It offers actionable insights for educators, researchers and policy makers aiming to support early learning by equipping young children with foundational skills critical for future academic and workforce success. Implications include the need for curriculum development, professional learning supports, and further research on interventions for infants, toddlers and children facing systemic barriers.