Research in the last decade has substantially advanced our understanding of the pathophysiology of heart failure with preserved ejection fraction (HFpEF). However, treatment options remain limited as clinical trials have largely failed to identify effective therapies. Part of this failure may be related to mechanistic heterogeneity. It is speculated that categorizing HFpEF patients based upon underlying pathophysiological phenotypes may represent the key next step in delivering the right therapies to the right patients. Echocardiography may provide valuable insight into both the pathophysiology and underlying phenotypes in HFpEF. Echocardiography also plays a key role in the evaluation of patients with unexplained dyspnea, where HFpEF is suspected but the diagnosis remains unknown. The combination of the E/e' ratio and right ventricular systolic pressure has recently been shown to add independent value to the diagnostic evaluation of patients suspected of having HFpEF. Finally, echocardiography enables identification of the different causes that mimic HFpEF but are treated differently, such as valvular heart disease, pericardial constriction, and high-output heart failure or infiltrative myopathies such as cardiac amyloid. This review summarizes the current understanding of the pathophysiology and phenotyping of HFpEF with particular attention to the role of echocardiography in this context.