Circadian rhythms are intrinsic 24-hour cycles regulating physiological and behavioral processes, including sleep, hormone release, and neurogenesis. Disruptions to these rhythms have been linked to neurodevelopmental disorders such as Fragile X Syndrome (FXS) and Autism Spectrum Disorder (ASD). This paper explores animal models to examine the effects of FXS on circadian rhythms and their neurobiological underpinnings. The Drosophila melanogaster dFMR1^B55 mutant model and FMR1-KO mouse model were utilized. The dFMR1^B55 model, studied using video-based behavioral systems, revealed increased sleep duration and fragmentation during light-dark cycles, indicating circadian rhythm disturbances. The FMR1-KO mouse model demonstrated reduced REM sleep and hyperactivity in hippocampal circuits, consistent with human FXS findings. These models highlight parallels between FXS-related circadian disruptions and neurological impairments, emphasizing their utility in understanding molecular mechanisms and potential therapeutic interventions. Future research could reveal how these disruptions affect neurogenesis and synaptic plasticity, providing avenues for addressing FXS-linked disorders.