Objective: Subclinical obsessive-compulsive (OC) symptoms are frequently observed in children and have been reported to predict a subsequent diagnosis of OC disorder (OCD). Therefore, identifying the putative neurobiological signatures of such risk is crucial, because it would allow for the characterization of the underpinnings of OCD without the interfering effects of chronicity, medication, or comorbidities, especially when interpreted within the context of OCD clinical heterogeneity and taking into account normal neurodevelopmental changes. The present study aimed to identify the brain volumetric features associated with subclinical OC symptoms and the potential modulatory effects of sex and age in a large sample of healthy children. Method: Two hundred fifty-five healthy children were assessed using the Obsessive-Compulsive Inventory Child Version and underwent a brain structural magnetic resonance examination. The relation between total and symptom-specific scores and regional gray and white matter (GM and WM) volumes was evaluated. Participants were grouped according to sex and age (younger versus older) to assess the effect of these factors on symptom brain morphometry associations. Results: Ordering symptoms were negatively related to GM volumes in the ventral caudate. Hoarding symptoms were positively associated with GM and WM volumes in the left inferior frontal gyrus, and obsessing symptoms correlated negatively with GM and WM volumes in the right temporal pole. Doubt-checking symptoms correlated positively with WM volumes in the right inferior fronto-occipital fasciculus and the corpus callosum. Sex and age modulated some of these associations. Conclusion: Subclinical OC symptoms are associated with specific brain volumetric features, which could be considered potential neural signatures of increased risk for OCD.