Chemical disorder leads to a variety of intriguing phenomena in alloys which have yet to be fully understood, particularly those phenomena occuring when chemical and magnetic effects interplay with one another. For example, magnetic order gives rise to chemical ordering in alloys, as in Ni-rich NiFe alloys. Two examples of the interplay of chemical disorder and magnetism will be discussed. Our recently developed ab-initio Landau (mean-field) theory for calculating the chemical-chemical, magneto-chemical, and magnetic-magnetic correlation functions in substitutional random alloys is used to describe electronic/magnetic mechanisms (e.g. in FeV) which give rise to the chemical short-range order as determined by neutron, X-ray, or electron diffuse scattering intensities. New developments within this approach that account for charge rearrangement effects will be mentioned. These calculations are performed within the multiplescatteringframework, developed by Korringa, Kohn, and Rostoker (KKR), combined with the coherent potential approximation (CPA) to describe the disorder. This approach allows a firstprinciples description of the electronic structure of the high-temperature, chemically disordered state and its instability to ordering at low temperatures. This method provides not only a direct comparison of diffuse scattering data with theory but a means to understand more fully the underlying mechanisms which drive chemical and/or magnetic ordering.