Liquid biopsy is a novel, non-invasive method for tumor assessment, yet to be implemented in CNS tumor diagnosis. Meningioma is a typically slow-growing, extra-axial tumor that arises from the arachnoid cap cells of the meninges and represents the most common primary intracranial neoplasm in adults, which is underexplored. This meta-analysis sought to evaluate the current landscape of overall diagnostic value of various liquid biopsy methods in meningioma. Following PRISMA 2020 and PRISMA-DTA extension guidelines, we systematically searched three databases, extracted data for 2×2 contingency tables, assessed methodological quality using QUADAS-2, and performed bivariate meta-analysis with R-based software. A total of 23 studies, from which 27 datasets, with a total number of 3,400 participants, were identified. The pooled overall sensitivity was 0.78 (95% CI: 0.71 – 0.83) and specificity was 0.82 (95% CI: 0.76 – 0.86), with an area under the curve (AUC) of 0.86. Subgroup analysis showed that seroreactivity assays had the highest accuracy (DOR = 67), while emerging technologies like cfDNA methylation showed high potential but were supported by limited data. Critically, we found strong evidence of publication bias (Deeks’ test, p < 0.001) and our meta-regression revealed that studies with a lower risk of bias reported significantly lower specificity (p = 0.008). While fluid-based biomarkers show good overall accuracy for meningioma diagnosis, the current evidence is compromised by significant heterogeneity and a high risk of bias, suggesting that true performance is likely more modest than reported. Future studies should focus on rigorously designed, prospective validations of key approaches, especially cfDNA methylation and seroreactivity, using appropriate control populations to clarify their clinical utility.