Background/Objectives: Alexithymia is a condition marked by difficulties in identifying and expressing emotions, rooted in both physiological and behavioral mechanisms. The aim of this study was to investigate the relationship between parental alexithymia and family functioning in families of children with Autism Spectrum Disorder (ASD) compared to families of typically developing children (TD). Methods: The study sample included parents of children with ASD (n = 120) and a control group of parents of typically developing children (n = 120). A comprehensive set of self-report instruments was used to evaluate alexithymia levels, parental stress, family experience, resilience, cognitive emotion regulation, social support, and family flexibility and cohesion. Results: The analysis revealed that parental alexithymia in families of children with ASD was directly associated with lower levels of family flexibility and cohesion, independent of increased stress or reduced family resilience. Furthermore, the findings indicate that alexithymia in parents is directly linked to reduced family cohesion in ASD families. Conclusions: These results highlight the significant role of parental alexithymia in shaping family dynamics and underscore the necessity for targeted interventions that emphasize emotional skill-building, adaptive coping mechanisms, and resilience to stressful events. This research enhances the understanding of parental alexithymia’s effect on family functioning in the context of ASD.