Vesta's surface composition provides insights on its internal structure, geological evolution, and space environment. The bulk igneous composition, the link to the howardite–eucrite–diogenite (HED) meteorites, and the differentiation into a crust and a mantle were confirmed by telescopic observations and by the Dawn mission. This chapter presents several key topics. The distribution of indigenous materials helps in understanding the structure and mineralogy of the crust and the thickness of the mantle as an insight to the geological evolution and history of the whole body. Hydroxylated, low-albedo areas indicate exogenous materials and widespread contamination of the surface by carbonaceous chondrites; this main result from the Dawn mission also has implications for the collisional history of Ceres. Finally, the characterization of surficial processes on Vesta clarifies the role of space weathering and lateral mixing. The surface composition studied from telescopic observations, geochemical measurements of the HED meteorites, and from the Dawn mission at Vesta is based on reflectance imaging spectroscopy, high-resolution imagery, and elemental data from gamma-ray and neutron spectroscopy. This chapter includes analyses of data from the Visible and InfraRed mapping spectrometer that benefited from improved instrument calibrations developed after the Dawn mission to Vesta and Ceres.