Background: Childhood dyslipidemia often tracks into adulthood and contributes to early atherosclerotic changes. Although serum 25-Hydroxyvitamin D (25(OH)D) has been implicated in lipid metabolism, findings in children remain inconsistent, and whether these associations differ by overweight/obesity (ow/ob) status is unclear. We therefore aimed to investigate the associations of serum 25(OH)D concentrations and lipid profiles stratified by ow/ob status among children and adolescents aged 9-17 years. Methods: This cross-sectional study included 3067 children and adolescents from Guangzhou, southern China. Anthropometric measurements were obtained by trained staff, and ow/ob status was classified according to WHO criteria. Fasting blood samples were collected to measure serum 25(OH)D and lipid parameters. Multivariable regression analyses were adopted to determine the associations between serum 25(OH)D and lipid profiles. Stratified analysis and interaction tests were further applied according to ow/ob status. Results: Higher 25(OH)D concentrations were most consistently associated with lower TG (β = -0.026; 95% CI, -0.040 to -0.011), higher HDL-C (β = 0.025; 95% CI, 0.014 to 0.035), and lower TG/HDL-C ratios (β = -0.044; 95% CI, -0.061 to -0.027). Positive associations were also observed for TC, LDL-C, and non-HDL-C with serum 25(OH)D, but these were attenuated after further adjustment for HDL-C. No significant association was observed for the TC/HDL-C ratio. In stratified analyses, associations with several lipid parameters were observed mainly among children and adolescents without ow/ob, whereas significant inverse associations among those with ow/ob were largely limited to TG and the TG/HDL-C ratio. Significant interactions between vitamin D and ow/ob status were observed for TC and non-HDL-C, but were attenuated after further adjustment for HDL-C. Conclusions: In this cross-sectional study, serum 25(OH)D was associated with several lipid parameters among children and adolescents, most consistently with TG, HDL-C, and the TG/HDL-C ratios. Stratified analyses showed different vitamin D-lipid association patterns across ow/ob status, with statistically significant interactions observed only for TC and non-HDL-C. The attenuation of several associations after adjustment for HDL-C suggests that HDL-C may be involved in these observed patterns. Future longitudinal studies are needed to examine causality of vitamin D-lipid associations and the potential role of HDL-C in these associations.