Introduction: Understanding gait alterations of children and adolescents with cerebral palsy (CP) classified at different levels of the Gross Motor Function Classification System (GMFCS) contributes to properly guided clinical reasoning. This study aims to identify a set of gait parameters that elucidate the gait profiles of children and adolescents with unilateral and bilateral spastic cerebral palsy (USCP; BSCP), according to their GMFCS level. Method: Cross-sectional study, 115 children/adolescents aged 7-17 years, GMFCS I-III, were evaluated using the Edinburgh Visual Gait Score. Categorical principal component (PC) analysis grouped gait deviations by CP type and GMFCS levels. Mann Whitney and One-Way ANOVA compared the PC scores between GMFCS I-II (USCP) and I-III (BSCP). Results: Two PCs explained 51.3% of the gait deviation variance (USCP). Individuals with GMFCS II showed alterations in their foot, knee, hip, and trunk joints in sagittal plane, that differentiate them from level I (p = 0.029). Among participants with BSCP, three PCs explained 53.3% of the variance. GMFCS II (p = 0.007) and III (p = 0.004) differed from level I in all lower limb joints, pelvis, and trunk. Discussion: Individuals with USCP/GMFCS II have a more flexed gait pattern than those with USCP/GMFCS I. Similarly, individuals with BSCP/GMFCS II and III showed alterations typically found in those with a crouch gait pattern. Conclusion: The alterations that can differentiate groups of functional mobility should be carefully evaluated, as these alterations are likely to cause greater functional impact in one group than in another.