Tuberous sclerosis complex (TSC) often co-occurs with neuropsychiatric disorders, although its association with obsessive-compulsive disorder (OCD) and obsessive-compulsive symptoms (OCS) has received limited attention. This systematic review and meta-analysis aimed to calculate the pooled point prevalence estimate of OCD and OCS in individuals with TSC as well as descriptively synthesise the clinical characteristics within this population. MEDLINE, Embase, Ovid Full Text, and PsycINFO were searched through April 2025, supplemented with backward and forward citation searching. Two reviewers independently screened full-text records to identify peer-reviewed English-language studies with primary data on OCD/OCS in individuals with TSC regardless of age. The included studies were then critically appraised via the Mixed-Methods Appraisal Tool. Data were extracted and synthesised using a random-effects meta-analysis of proportions, a meta-regression of assessment type, and subgroup analyses of age and genotype. Heterogeneity was quantified via I2 and 𝜏2. Sixteen studies met the eligibility criteria for the systematic review, of which 10 were included for the meta-analysis of proportions. The 10 studies (n = 1,429) produced a pooled point prevalence of 10.0% [95% CI: 5.2–18.3%; I2 = 87.6%; 𝜏2 = 0.711; p < 0.0001]. Neither assessment type, age, nor genotype significantly affected the point prevalence estimate. Despite notable clinical characteristics and a significant association between TSC and OCD/OCS, no preregistration and considerable heterogeneity render these results as exploratory and requiring cautious interpretation. Future studies—with prospective designs and more-diverse participant sources—will ensure more precise prevalence estimates and increased generalisability.