<p>Circular RNAs (circRNAs) have emerged as important regulators of tumor progression; however, their roles in papillary thyroid carcinoma (PTC) remain incompletely understood. In this study, we investigated the expression, biological function, and molecular mechanism of circGABRB2_006 in PTC. CircGABRB2_006 was significantly upregulated in PTC tissues and cell lines and was associated with aggressive clinicopathological characteristics, including increased tumor number, larger tumor size, advanced TNM stage, and lymph node metastasis. Functional assays demonstrated that circGABRB2_006 promoted PTC cell proliferation, migration, invasion, epithelial–mesenchymal transition (EMT), tumor growth, and pulmonary metastasis, whereas its silencing exerted the opposite effects. Mechanistically, circGABRB2_006 predominantly localized in the cytoplasm and acted as a molecular sponge for miR-296-5p, thereby relieving miR-296-5p-mediated repression of fibroblast growth factor receptor 1 (FGFR1). Rescue experiments further confirmed that the oncogenic effects of circGABRB2_006 were largely dependent on the miR-296-5p/FGFR1 axis. Collectively, these findings demonstrate that circGABRB2_006 drives malignant progression of PTC through the miR-296-5p/FGFR1 signaling axis, highlighting its potential as a biomarker and therapeutic target in PTC.</p> Graphical Abstract <p></p>