Background: Recurrence and metastasis are the main causes of non-small cell lung cancer (NSCLC)-related death. CD146 has been identified as a potential risk factor for poor prognosis, closely related to the distant metastasis and drug resistance in various cancers. However, the clinical significance of CD146 in NSCLC requires further investigation. Materials and Methods: This study explored the correlation between CD146 expression and clinical variables using tumor tissue samples collected from our hospital. CD146 expression levels in NSCLC cell lines and tissues were assessed and compared using immunohistochemistry, real-time polymerase chain reaction (RT-qPCR), flow cytometry, and western blot analysis. The invasion and migration capabilities of tumor cells were determined using transwell and wound healing assays. The levels of proteins related to epithelial-mesenchymal transition (EMT) as well as the underlying PI3K/Akt signaling pathway was measured by western blotting. Results: We discovered that CD146 expression is significantly associated with the EMT signaling pathway. High CD146 expression predicted lymph node metastasis, metastasis to distant organs, advanced Tumor, Node, Metastasis (TNM) staging, and poor survival in NSCLC patients. Wound healing and transwell assays showed that knocking down CD146 significantly suppressed cell migration along with cell invasion in NSCLC, whereas overexpressing CD146 notably enhanced these processes. Western blot analysis revealed significantly reduced levels of N-cadherin, vimentin, snail, twist, PI3K, and AKT phosphorylation in shCD146 H460 cells compared to vector control cells. Treatment with PI3K inhibitor PI3K-IN-1 increased E-cadherin expression levels but reduced N-cadherin, Twist, Vimentin, PI3K, and AKT phosphorylation levels in pcDNA3.1-CD146 A549 cells compared with the vector control cells. Conclusions: CD146 expression acts as a prognostic risk factor for adverse outcomes in NSCLC, promoting invasion and metastasis by activating the EMT through the PI3K/Akt signaling pathway. These findings underscore the potential therapeutic strategies targeting CD146, offering new treatment options for NSCLC patients, especially those at risk of metastasis.