Molecular mechanisms underlying thyroid tumorigenesis and identifying new therapeutic targets are still under investigation. We aim to investigate the role of CD146 and latexin (Lxn) and examine whether they have any clinical significance in thyroid cancer. Human thyroid papillary (PTC), follicular (FTC), anaplastic (ATC) cancer cells, and other control cells were used in this study. Western blot, cell proliferation, invasion assay, and shRNA were applied to study the expression levels and functional significances of CD146 and Lxn in thyroid cells. The protein expression was evaluated by immunohistochemistry using human tissue microarray (TMA) slides. Multivariate analysis was used to examine whether these proteins have any clinical significance in patients with thyroid cancer. The protein expressions of CD146 and Lxn were detected in most thyroid cancer cell lines when compared with normal cells. Notably, knockdown of CD146 reduced the migration and invasion in K1 (PTC) and OCUT-1 (ATC) cells. TMAs showed more immunoreactivity against CD146 and Lxn in PTC cores compared with FTC, ATC, and normal tissues. A positive correlation was established between CD146 and both Lxn (r = 0.421, p = 0.045) and age (r = 0.566, p = 0.012); however, it showed a negative correlation with tumor stage (r = -0.231, p = 0.010). In conclusion, CD146 and Lxn increased tumor migration and invasion in vitro and showed a high expression in PTC compared to those in ATC and normal human tissues demonstrating their role in early stage of thyroid tumorigenesis. CD146 was positively correlated with age, but negatively correlated with tumor stage.