Healthy eating habits, which start with food introduction, can influence children's growth and development. Therefore, the educational actions carried out at school for children who are beginning to eat, involving families and school staff who attend daycare centers, can serve as strategies to improve complementary feeding practices. This review will analyze the effectiveness of early childhood education interventions to improve complementary feeding practices in children aged 4 to 36 months. The review will consider randomized clinical trials, cluster-randomized clinical trials, and controlled clinical trials that evaluate the effectiveness of early childhood education interventions involving children aged 4 to 36 months, their families, or school staff to improve complementary feeding. In their absence, observational cohort, case-control, and cross-sectional studies may be considered. This review will be conducted in line with the JBI methodology for systematic reviews of effectiveness. The search for relevant studies will be conducted in PubMed, Embase (Ovid), BIREME, Scopus, the Cochrane Library (Cochrane Central Register of Controlled Trials CENTRAL and Cochrane Database of Systematic Reviews), CINAHL (EBSCOhost), and the ProQuest Databases (ProQuest Central). No date or language limitation will be applied. Two independent reviewers will select studies by screening titles, abstracts, and keywords against the inclusion criteria. This will be followed by full-text screening. Two independent reviewers will then conduct the study method quality evaluation and data extraction. GRADEpro will be used to assess the certainty in the findings, which will be reported in a systematic review, and, if possible, grouped in a meta-analysis. PROSPERO CRD42022384704.