Abstract Body: Aging and obesity promote metabolic and arterial dysfunction. Increased cellular senescence and the senescence-associated secretory phenotype (SASP) play a key role in development of age-related cardiometabolic dysfunction by augmenting inflammation and oxidative stress. We fed middle-aged (12–15 months) C57BL/6 mice a high-fat diet to model the combined age- and obesity-related metabolic and arterial dysfunction observed in humans. We hypothesized that obesity would exacerbate age-related metabolic and arterial dysfunction and would be associated with increased senescent cell burden and SASP factor expression. To test the contribution of cellular senescence, high-fat diet fed mice were treated with either the senolytic cocktail of dasatinib (D; 5 mg/kg) and quercetin (Q; 50 mg/kg) or vehicle (saline) for 3 consecutive days every 2 weeks over a 3-month period (n = 10 per group).Treatment with D&Q reduced gene expression of p21, a senescence marker, in perigonadal white adipose tissue (p=0.03). Moreover, this treatment attenuated the gene expression of several SASP including mcp1, tnf-α, il-1α, il-1β, and il-6 in both adipose tissue and liver (all p≤0.05). As expected, aging and obesity increased arterial stiffness, as assessed by aortic pulse wave velocity (p<001), and D&Q treatment prevented the increase in arterial stiffness driven by obesity and aging. Likewise, endothelium-dependent dilation to acetylcholine, assessed using pressure myography, was significantly impaired in mesenteric arteries from obese mice, and D&Q prevented this deleterious effect (p=003). The difference in vasodilation between D&Q and vehicle treated mice was abolished when acetylcholine was introduced in the presence of nitric oxide synthase inhibitor, L-NAME (p=0.373), suggesting that the D&Q improved vasodilation by restoring nitric oxide bioavailability. Glucose (2 g/kg body mass, IP, GTT) and insulin (1 U/kg body mass, IP, ITT) tolerance tests were performed in fasted (4-6 hr) mice to assess systemic metabolic function. D&Q treatment prevented high fat diet induced glucose intolerance (p=0.014) and insulin resistance (p=0.001). These findings suggest that senolytic therapy may be an effective strategy to improve cardiometabolic health in aging and obesity by lowering inflammation and improving NO bioavailbility.