While many studies have suggested that heart failure (HF) may lead to cognitive impairment, our understanding about this relationship is limited. This study investigated the association of cognitive function with HF risk factors and how cognitive impairment may impact the development of incident clinical HF in people with subclinical HF. People with either preclinical (at risk and asymptomatic, n=814) or clinical (symptomatic, n=1152) HF were recruited from communities, clinics, and hospitals in 5 Australian states (Victoria, New South Wales, South Australia, Tasmania, and Queensland). Cognitive impairment was measured with the Montreal Cognitive Assessment (MOCA <26). Left ventricular dysfunction was assessed as global longitudinal strain (<16%). Patients with preclinical HF were followed up for 45±13 months for incident clinical HF or death. Baseline MOCA was independently associated with age, HF stage, diabetes, atrial fibrillation, chronic lung disease, cerebrovascular disease, global longitudinal strain, left atrial volume index, and left ventricular filling pressure. Cognitive impairment significantly increased the associations of age (interaction <i>P</i><0.001), comorbidity index (interaction<0.001), and global longitudinal strain (interaction <i>P</i>=0.042) with clinical HF. Of patients with preclinical HF at baseline, 71 (9%) developed clinical HF and 87 (11%) died within the follow-up period. In time-to-event analysis of participants with preclinical HF, those with either cognitive impairment or left ventricular dysfunction had double the risk of developing clinical HF, compared with those with normal cognition and left ventricular function. Those with concomitant cognitive impairment and left ventricular dysfunction had a 4-fold greater risk of developing HF (subdistribution hazard ratio, 4.01 [95% CI, 2.39-6.76]). Cognitive impairment is associated with increased risk of incident clinical HF, independent of cardiac function and other HF risk factors.