Lung adenocarcinoma is a crucial contributor to cancer-related mortality; however, effective treatments remain challenging. The present study aimed to investigate the role of hemoglobin subunit theta 1 (HBQ1), an α subunit of hemoglobin whose expression has recently been reported in non-erythroid cells, in lung adenocarcinoma. Comparative analysis showed that HBQ1 expression was significantly higher in lung adenocarcinoma tissues compared to normal lung tissues. Moreover, high HBQ1 expression was correlated with unfavorable overall survival and progression-free survival in patients, highlighting its potential as a prognostic marker. Our functional experiments revealed that when overexpressed, HBQ1 acts as an oncogene, enhancing cell proliferation, whereas HBQ1 knockdown inhibits it. Additionally, HBQ1 exhibited antioxidant properties by reducing basal reactive oxygen species levels, playing a crucial role in lung adenocarcinoma progression. These findings emphasize the critical role of HBQ1 in driving tumor growth and progression in lung adenocarcinoma. Our in vivo studies further supported the role of HBQ1 in lung adenocarcinoma. HBQ1 knockdown resulted in the inhibition of lung adenocarcinoma growth, demonstrating the potential of HBQ1 as a therapeutic target. Our findings highlight the importance of HBQ1 in lung adenocarcinoma and suggest its potential as both a diagnostic marker and a molecular target for therapeutic interventions.