The development of highly efficient visible-light photocatalysts is of great significance in the area of environmental decontamination and energy conversion. Especially, photocatalysts with ultrathin two-dimensional nanostructures have attracted tremendous attention because of their unique quantum size and surface effects. Here, we prepare for the first time the quasi-two-dimensional ultrathin iron vanadium oxide (FeV3O8) nanoplatelets with a thickness of only 2.75 nm by a pH-controlled hydrothermal reaction. The Brunauer-Emmett-Teller (BET) surface area of the FeV3O8 nanoplatelet is measured to be 162.35 m(2) g(-1), which is about 3.2-fold higher than that of commercial P25, and is significantly higher than those reported for vanadates with similar structures. Importantly, these ultrathin nanoplatelets demonstrate good stability under visible-light irradiation (lambda >= 400 nm), highly efficient recycling utilization, and superior photo-catalytic activity as compared with conventional photocatalysts and structurally similar vanadates, holding significant potential for further applications in environmental decontamination.