The speciation of arsenic (As) in a copper-chromated-arsenate (CCA) contaminated soil was investigated using micro-focused X-ray fluorescence ( μ XRF ) and micro-focused X-ray absorption fine structure ( μ XAFS ) spectroscopies to determine if and how the co-contaminating metal cations (Cu, Zn, Cr) influenced the speciation of As. 15 μ XRF images were collected on 30-μm polished thin sections and powder-on-tape samples from which Pearson correlation coefficients ( ρ ) between As and various metal species were determined based on the fluorescence intensity of each element in each image pixel. 29 μ XAFS and two bulk-XAFS spectra were collected from depths of 0–20 cm (LM-A) and 20–40 cm (LM-B) to determine the chemical speciation of As in the soil by target analyses of principal components with circa 52 reference spectra and linear least-square combination fitting of individual experimental spectra with a refined reference phase list (32) of likely As species. Arsenic and metal cations (Cr, Mn, Fe, Cu, Zn) accumulated in distinct, isolated areas often not larger than 50 × 50 μm in which the Pearson correlation between the elements was strongly positive ( ρ > 0.75 ) . The correlation of As to Zn and Cr decreased from >0.9 to <0.8 and increased to Cu from ∼0.6 to >0.8 with depth. Arsenic occurred predominantly in the +5 oxidation state. Abstract factor analysis and linear least square combination fit analysis suggested that As occurred as a continuum of fully and poorly-ordered copper-arsenate precipitates with additional components being characterized by surface adsorption complexes on goethite and gibbsite in the presence and absence of Zn. Precipitates other than copper-based ones, e.g., scorodite, adamite and ojuelaite were also identified. The significant co-localization and chemical speciation of As with Cu suggest that the speciation of As in a contaminated soils is not solely controlled by surface adsorption reactions, but significantly influenced by the co-contaminating metal cation fraction. Future studies into As contaminated soil therefore need to focus on identifying the speciation of As and the co-localizing metal cations.