Background <p>Cerebral palsy (CP), a prevalent motor disorder in children, is characterized by movement and posture issues due to non-progressive brain damage. Spastic CP, the most prevalent subtype, significantly impacts gross motor functions and independence in daily life. The foot, which we stand on the ground with, contributes to maintaining our balance and initiating the stance phase of gait. Therefore, examining abnormalities and functionality in foot posture in CP is important to better understand the possible effects on balance and gait while standing. This study compares balance, foot posture, functionality, and gait speed of spastic CP across Gross Motor Function Classification System (GMFCS) levels, providing insights into rehabilitation strategies.</p> Materials and methods <p>Eighty children (40 with spastic CP and 40 typically developing peers) were included, aged between 7 and 16&#xa0;years. Participants were assessed for gross motor functions (GMFM), balance, foot posture, functionality, and gait speed (10-m walk test). Randomization ensured equal distribution across GMFCS levels I–III for the CP group. Sociodemographic data and clinical measures were recorded.</p> Results <p>Children with CP exhibited significantly lower gross motor function, balance, and foot functionality scores than their typically developing peers. However, no significant difference was noted in foot posture. Across GMFCS levels, increasing severity correlated with worsened motor functions, balance, and gait speed. Level III showed the most pronounced impairments.</p> Conclusions <p>Spastic CP adversely impacts gross motor function, balance, and gait, which worsens with increasing GMFCS levels. Early and comprehensive evaluations of motor functions and related parameters are critical for tailored interventions. Further studies are recommended to enhance therapeutic strategies and outcomes.</p>