The anti-inflammatory, antioxidative, and antiarteriosclerosis activities of simvastatin along with its protective effects on the endothelium suggest that it may also have antiaging effects. The aim of this study was to investigate the antiaging effects of simvastatin as well as its effects on sirtuin 1 (SIRT1) expression in endothelial cells. Aged rats and human umbilical vein endothelial cells were treated with simvastatin in the presence and absence of oxidized low-density lipoprotein (OX-LDL). Aortic β-galactosidase staining was undertaken to determine senescence, and SIRT1 protein expression was evaluated using Western blot analysis. After simvastatin therapy, arterial endothelial cell aging was significantly reduced, and SIRT1 expression was significantly increased. The OX-LDL significantly accelerated the senescence of umbilical vein endothelial cells and decreased SIRT1 expression. The OX-LDL-induced downregulation of SIRT1 was blocked by simvastatin. Simvastatin treatment also reduced umbilical vein endothelial cell aging and increased SIRT1 expression.