This paper presents the findings from a systematic review of 29 websites and 13 frameworks that provide STEM (Science, Technology, Engineering, Mathematics) educational resources for parents, educators, and children (birth–8 years of age). Our theoretical approach is rooted within a social semiotic perspective that has indicated that multimodality enables children to use different types of expression to communicate a message or share an idea. Using the PRISMA methodology and the narrative document analysis approach, the themes that emerged included how the content and resources available on the websites addressed whether multimodality supported STEM engagement in an inclusive manner. The findings revealed that there were scarce multimodal resources that engaged children with fun, interactive, and meaningful opportunities to be autonomous learners (e.g., children had agency) (n = 11 out of 29), moving between the digital and hands-on physical spaces (n = 8 out of 29), employing gamification for deep learning (n = 4 out of 29), and piquing children’s imagination, inquiry, and creativity, and links to everyday STEM scenarios were hardly present (n = 10 out of 29). The implications lie in addressing early STEM engagement by considering children’s learning abilities and agency, bearing in mind parents/educators’ sociocultural backgrounds, confidence in STEM awareness, and multimodal avenues for communicating STEM learning and inquiry.