Lung cancer is one of the most common and aggressive cancer and a leading cause of cancer related deaths worldwide. Few studies have prospectively examined the functions of SH3GL3 in cancer progression, however, the biological functions of SH3GL3 in lung cancer initiation and progression remains largely unknown. Here, we show that both mRNA and protein levels of SH3GL3 are weakly expressed in lung cancer tissues and cell lines and its expression negatively correlates with the survival of lung cancer patients. Overexpression of SH3GL3 dramatically inhibits lung cancer cells malignancy behaviors, including proliferation and migration. Additionally, SH3GL3 curbs cell cycle at G0/G1 phase and induces cellular apoptosis of lung cancer cells and inhibits lung cancer stem cell self-renewal dependents on its SH3 domain. Moreover, we report for the first time that SH3GL3 inhibits lung cancer progression partially through p21 and up-regulates p21 in transcriptional level. Collectively, our work suggests that SH3GL3 acts as a potent tumor suppressor in lung cancer progression and have a potential to serve as diagnostic and prognostic biomarker of lung cancer. (C) 2020 Elsevier Inc. All rights reserved.