Objective: Dysregulation of the Wnt/β-catenin signaling system has been increasingly associated with the pathogenesis of autism spectrum disorder (ASD). Nevertheless, regulators of this system remain unexamined in patients with ASD. This study aimed to examine serum concentrations of Dkk-1, PORCN, Notum, and Tiki-1 in preschool children with ASD. Methods: A total of 60 children diagnosed with ASD and 50 healthy controls, aged 18 to 60 months, were included in the study. Serum levels of the target molecules were quantified utilizing enzyme-linked immunosorbent assay kits. Autism severity and behavioral traits were evaluated utilizing the Childhood Autism Rating Scale (CARS) and the Autism Behavior Checklist (AuBC). Results: Serum concentrations of Dkk-1 and PORCN were significantly higher in the ASD group relative to controls. However, no significant difference for serum Notum and Tiki-1 levels was detected between the groups. Correlation analyses revealed significant positive associations between serum PORCN, Notum, and Tiki-1 levels and multiple AuBC subscale and total scores. No significant correlations were found between any of the molecules and CARS scores. Conclusion These data indicate that regulators of the Wnt/β-catenin pathway, notably Dkk-1 and PORCN may play a potential role in the pathogenesis of ASD. This study presents new data confirming the significance of Wnt/β-catenin pathway regulators in ASD and underscores the necessity for further research.