This chapter will summarize the most recent data available for sulfate and phosphate transport in mammalian renal and gastrointestinal systems. Dietary derived sulfate and phosphate are absorbed in the intestines and their circulating levels are controlled by renal tubular mechanisms. Such processes are facilitated by sulfate and phosphate transporters that exist in the epithelial cells of the kidneys and intestines. Sulfate transporters belong to two gene families, the Na+-coupled sulfate transporters (SLC13) and the sulfate anion exchangers (SLC26). Phosphate transporters belong to three gene families, Type I (SLC17), Type II (SLC34), and Type III (SLC20) of which all members are Na+-coupled phosphate transporters. Tissue distribution for these transporters is diverse, with some being restricted to either renal or intestinal tissues and with others showing more broad tissue distribution. Various modes of regulation affect the expression of these genes and the proteins they encode in their respective tissues. Lessons from knock-out mice reveal the physiological (and pathophysiological) roles these proteins play in the body and their contributions to sulfate and phosphate homeostasis.