Background Studies have suggested that sodium glucose co-transporter 2 inhibitors exert anti-inflammatory effects. We examined the association of baseline growth differentiation factor-15 (GDF-15), a marker of inflammation and cellular injury, with cardiovascular events, hospitalization for heart failure (HF), and kidney outcomes in patients with type 2 diabetes in the CANVAS (Canagliflozin Cardiovascular Assessment Study) and determined the effect of the sodium glucose co-transporter 2 inhibitor canagliflozin on circulating GDF-15. Methods and Results The CANVAS trial randomized 4330 people with type 2 diabetes at high cardiovascular risk to canagliflozin or placebo. The association between baseline GDF-15 and cardiovascular (non-fatal myocardial infarction, non-fatal stroke, cardiovascular death), HF, and kidney (40% estimated glomerular filtration rate decline, end-stage kidney disease, renal death) outcomes was assessed using multivariable adjusted Cox regression models. During median follow-up of 6.1 years (N=3549 participants with available samples), 555 cardiovascular, 129 HF, and 137 kidney outcomes occurred. Each doubling in baseline GDF-15 was significantly associated with a higher risk of cardiovascular (hazard ratio [HR], 1.2; 95% CI, 1.0‒1.3), HF (HR, 1.5; 95% CI, 1.2‒2.0) and kidney (HR, 1.5; 95% CI, 1.2‒2.0) outcomes. Baseline GDF-15 did not modify canagliflozin's effect on cardiovascular, HF, and kidney outcomes. Canaglifozin treatment modestly lowered GDF-15 compared with placebo; however, GDF-15 did not mediate the protective effect of canagliflozin on cardiovascular, HF, or kidney outcomes. Conclusions In patients with type 2 diabetes at high cardiovascular risk, higher GDF-15 levels were associated with a higher risk of cardiovascular, HF, and kidney outcomes. Canagliflozin modestly lowered GDF-15, but GDF-15 reduction did not mediate the protective effect of canagliflozin.