Although the roots and flowers of P. thunbergiana are known to have various physiologically active effects, studies on the anti-melanin production and anti-photoaging effects of its leaf extracts and cellular mechanisms are still lacking. In this study, we evaluated the possibility of using Pueraria thunbergiana leaves as a natural material for skin whitening and anti-aging-related functional cosmetics. The 30% ethyl alcohol (EtOH) extract from P. thunbergiana leaves was fractionated using n-hexane, ethyl acetate (EtOAc), butanol, and aqueous solution to measure their whitening, and anti-aging effects. The EtOAc fraction contained a high content of phenolic and flavonoids and showed higher 1,1-diphenyl-2-picryhydrazyl (DPPH) and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activities than the other fractions. It was also confirmed that the EtOAc fraction markedly inhibited α-melanocyte stimulating hormone (α-MSH)-induced melanogenesis in B16F10 melanoma cells. In addition, the EtOAc fraction showed a protective effect against ultraviolet B (UVB) in HaCaT cells and increased the collagen synthesis that was decreased due to UVB exposure. Matrix metalloproteinase-1 (MMP-1) activity and MMP-1 protein expression were reduced in human epidermal keratinocytes (HaCaT) cells. These results indicate that the EtOAc fraction has superior antioxidant activity, anti-melanogenesis, and anti-photoaging effects compared to the other fractions. Therefore, in this study, we confirmed the potential of P. thunbergiana leaf extract as a functional cosmetic ingredient, and it can be used as basic data for the physiological activity of P. thunbergiana leaf extracts.