There have been global efforts to achieve the sustainable development goals (SDGs) on quality education, gender equality, industry, innovation, and infrastructure development; however, in science, technology, engineering, and mathematics (STEM), men still dominate these fields at the highest levels, as boys dominate STEM subjects in schools. Thus, there is a need to improve female participation in these fields at all levels. Therefore, this systematic review examined the empirical evidence on the factors affecting girls' participation in STEM subjects. We conducted a comprehensive literature search using electronic databases such as Web of Science, Scopus, EBSCO‐host, and Google Scholar. An analysis of 165 scholarly publications was done using a systematic methodology. The study found that only 10% of the studies indicated that girls' poor participation in STEM could be attributed to personal factors and 61% to environmental factors. Additionally, behavioral factors accounted for 29% of the sampled studies, which found that negative attitudes, lack of career plans, lack of collaboration, interest, poor self‐concept, self‐efficacy, and low motivation were identified as factors that affect girls' participation in STEM subjects. The findings highlight a comprehensive overview of the current knowledge of girls in STEM, providing policymakers, educators, and practitioners with valuable insights into creating an enabling environment that supports more girls in STEM subjects. Furthermore, it contributes to the global efforts to achieve the SDGs 4, 5, and 9.