C6orf141 (Chromosome 6 open reading frame 141) is a novel gene, and its role in oral cancer progression remains unclear. C6orf141 expression in oral squamous cell carcinoma (OSCC) and adjacent normal tissues from 428 patients was examined through immunohistochemistry (IHC). Our results revealed that C6orf141 expression was significantly reduced in OSCC compared with adjacent normal tissues. Low C6orf141 expression was significantly associated with a poor American Joint Committee on Cancer pathological stage (P < 0.001), T classification (P = 0.002), and pN stage (P = 0.032). Kaplan-Meier curves revealed that low C6orf141 expression was significantly associated with shorter disease-specific survival (DSS) in patients with OSCC (log-rank P = 0.007). Multivariate analysis indicated that low C6orf141 expression was an independent prognostic biomarker for DSS (adjusted hazard ratio = 1.34; 95% confidence interval = 1.10-1.81; P = 0.05). Additionally, ectopic C6orf141 expression could significantly suppress oral cancer cell proliferation, colony formation, and migratory and invasive abilities. Xenograft tumor growth assay revealed that C6orf141 could significantly suppress oral tumor growth in vivo. Our results suggest that C6orf141 plays a novel tumor-suppressive role in oral cancer cell growth and motility. Furthermore, C6orf141 dysfunction could be a potential prognostic biomarker for OSCC and provide new therapeutic strategies in the future.