ABSTRACT Aim Steroidal mineralocorticoid receptor antagonists (MRAs), spironolactone and eplerenone, are strongly recommended in the treatment of patients with chronic heart failure (HF) with reduced left ventricular ejection fraction (LVEF), but the balance of efficacy and safety in those with higher LVEF has not been well established. Broad use of steroidal MRAs has further been limited in part due to safety concerns around risks of hyperkalaemia, gynecomastia, and kidney dysfunction. These risks may be mitigated by the unique pharmacological properties of the non‐steroidal MRA finerenone. The FINEARTS‐HF trial is designed to evaluate the long‐term efficacy and safety of the selective non‐steroidal MRA finerenone among patients with HF with mildly reduced or preserved ejection fraction. Methods FINEARTS‐HF is a global, multicentre, event‐driven randomized trial evaluating oral finerenone versus matching placebo in symptomatic patients with HF with LVEF ≥40%. Adults (≥40 years) with HF with New York Heart Association class II–IV symptoms, LVEF ≥40%, evidence of structural heart disease, and diuretic use for at least the previous 30 days were eligible. All patients required elevated natriuretic peptide levels: for patients in sinus rhythm, N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) ≥300 pg/ml (or B‐type natriuretic peptide [BNP] ≥100 pg/ml) were required, measured within 30 days (in those without a recent worsening HF event) or within 90 days (in those with a recent worsening HF event). Qualifying levels of NT‐proBNP or BNP were tripled if a patient was in atrial fibrillation at screening. Estimated glomerular filtration rate <25 ml/min/1.73 m 2 or serum potassium >5.0 mmol/L were key exclusion criteria. Patients were enrolled irrespective of clinical care setting (whether hospitalized, recently hospitalized, or ambulatory). The primary endpoint is the composite of cardiovascular death and total (first and recurrent) HF events. The trial started on 14 September 2020 and has validly randomized 6001 participants across 37 countries. Approximately 2375 total primary composite events are targeted. Conclusions The FINEARTS‐HF trial will determine the efficacy and safety of the non‐steroidal MRA finerenone in a broad population of hospitalized and ambulatory patients with HF with mildly reduced or preserved ejection fraction. Clinical Trial Registration: ClinicalTrials.gov NCT04435626 and EudraCT 2020‐000306‐29.