Aronia berries (Aronia melanocarpa and Aronia mitschurinii) are underutilized functional food, rich in bioactives. Aronia berries have abundant levels of anthocyanins, proanthocyanidins, flavonols, and phenolic acids that may reduce the risk of non-communicable diseases such as diabetes, metabolic syndrome, and neurological disease. Aronia polyphenols are bioavailable, and the majority are transformed into low molecular-weight phenolics. The impact of biotransformation on aronia polyphenols health effects is not fully understood. The objective of this review is to analyze aronia berry composition, including polyphenols nutrients. Additionally, this review summarizes recent preclinical and clinical studies on the polyphenol bioavailability and health benefits upon aronia berry consumption to better understand its potential as a functional food.