Solute carrier family 22 member 8, or organic anion transporter 3 (OAT3), is a protein that in humans is encoded by the SLC22A8 gene. This gene encodes a protein involved in the sodium-independent transport and excretion of organic anions, some of which are potentially toxic. The encoded protein is an integral membrane protein and appears to be localized to the basolateral membrane of the kidney. Multiple alternatively spliced transcript variants that encode different protein isoforms have been described for this gene.