Objectives This study aimed to evaluate the efficacy and safety of finerenone, a selective, non-steroidal mineralocorticoid receptor antagonist, on cardiovascular and kidney outcomes by age and/or sex.Design FIDELITY post hoc analysis; median follow-up of 3 years.Setting FIDELITY: a prespecified analysis of the FIDELIO-DKD and FIGARO-DKD trials.Participants Adults with type 2 diabetes and chronic kidney disease receiving optimised renin–angiotensin system inhibitors (N=13 026).Interventions Randomised 1:1; finerenone or placebo.Primary and secondary outcome measures Cardiovascular (cardiovascular death, non-fatal myocardial infarction, non-fatal stroke or hospitalisation for heart failure (HHF)) and kidney (kidney failure, sustained ≥57% estimated glomerular filtration rate (eGFR) decline or renal death) composite outcomes.Results Mean age was 64.8 years; 45.2%, 40.1% and 14.7% were aged