Background: Lung adenocarcinoma (LUAD) is the predominant histological subtype among non-small cell lung cancer cases, representing approximately 40% of all cases. Shugoshin 2 (SGO2) is implicated in tumorigenesis and tumor progression. This study aimed to uncover a potential role of SGO2 in the LUAD. Methods: Data related to gene mRNA expression and clinical information were obtained from The Cancer Genome Atlas (TCGA), The Genotype-Tissue Expression (GTEx), and the Cancer Cell Line Encyclopedia (CCLE) databases. Cell Counting Kit-8 (CCK-8), Transwell, scratch assay, and flow cytometry were applied to investigate the biological functions of SGO2 in the LUAD. Western blot was conducted to detect the protein expression. Results: Through pan-cancer analysis, SGO2 was found to be consistently overexpressed in 25 of 33 cancer types, including LUAD. In vitro assays revealed that SGO2 knockdown significantly impeded cell proliferation, cell migration, invasion and epithelial-mesenchymal transition (EMT), whereas its overexpression promoted these abilities. Flow cytometry confirmed that SGO2 contributed to cell cycle progression and reduced cell apoptosis. Furthermore, SGO2 facilitated cell proliferation and regulated cell cycle through upregulating recombinant E2F transcription factor 1 (E2F1). Conclusions: Our study demonstrated that SGO2 was up-regulated in pan-cancers including LUAD and its high expression was strongly associated with poor overall survival (OS) and progression-free survival (PFS) of patients with LUAD. SGO2 promoted cell proliferation, cell migration, invasion and EMT of A549 cells. Additionally, E2F1 was involved in regulation of cell cycle and cell proliferation mediated by SGO2. This research elucidated the oncogenic significance of SGO2 in LUAD, proposing its potential as a prognostic biomarker and a promising target for therapeutic interventions.