A storage tank assembly for a work vehicle includes a frame assembly configured to couple to a structure of the work vehicle. The storage tank assembly also includes a storage tank configured to store a liquid. The frame assembly is configured to support the storage tank on the structure of the work vehicle. In addition, the frame assembly is configured to position a first portion of the storage tank above a wheel assembly of the work vehicle, the first portion of the storage tank is contoured to substantially match a curvature of the wheel assembly, and the frame assembly is configured to position a second portion of the storage tank laterally inward of the wheel assembly such that the second portion of the storage tank extends within a vertical extent of the wheel assembly.