Anthocyanins are plant-derived natural pigments commonly present in many fruits and responsible for their red, blue, and violet/purple color. Many anthocyanin-rich fruits are consumed in the human diet. This chapter describes the chemistry and occurrence of anthocyanins in fruits. Anthocyanins can be categorized as nonacylated and acylated anthocyanins based on the absence or presence of the acyl group. The stability of nonacylated and acylated anthocyanins is discussed in this chapter. The biological activities of anthocyanins from fruits covered in this chapter include antioxidant, anticancer, and antimicrobial activities.