Background and Aims: Vascular calcification (VC), a major contributor to cardiovascular morbidity and mortality particularly in patients with diabetes and chronic kidney disease (CKD), is an active cell-driven process involving osteogenic differentiation of vascular cells. Adenosine 2A receptor (ADORA2A) is highly expressed in vascular cells and associated with coronary artery disease; its role in VC remains unclear. This study aims to investigate the effects of ADORA2A on VC and evaluate whether ADORA2A is a potential therapeutic target for VC. Methods: Cultured vascular cells and mouse aortas were treated with osteogenic medium (OM) to establish in vitro and ex vivo models. VC in mice was induced by a combination of 5/6 th nephrectomy, a high phosphate diet, and a vitamin D supplement. The effects of ADORA2A on vascular calcification were evaluated by calcium deposition, alkaline phosphatase activity, and changes of osteogenic markers and vascular phenotypic markers. Results: ADORA2A expression was upregulated in OM-treated vascular cells and aortas, aortas of CKD mice, and calcified tibial arteries of patients. Mice with Adora2a global or vascular-specific deficiency or treatment with an ADORA2A pharmacological antagonist displayed attenuated calcium deposition and decreased expression of osteogenic markers in calcified aortas. The same findings were observed in in vitro and ex vivo assays. Mechanistically, ADORA2A-mediated osteogenic differentiation in vascular cells was mediated by hypoxia-inducible factor-1A (HIF1A). Conclusion: ADORA2A inactivation mitigates osteogenic differentiation of vascular cells and aortic calcification by downregulating HIF1A activation; therefore, blocking ADORA2A holds promise for treating VC.