The SPARC T3 microprocessor is a multithreading, multi-core CPU produced by Oracle Corporation. Officially launched on 20 September 2010, it is a member of the SPARC family, and the successor to the UltraSPARC T2.

A multi-core processor is a microprocessor on a single integrated circuit with two or more separate processing units, called cores, each of which reads and executes program instructions. The instructions are ordinary CPU instructions but the single processor can run instructions on separate cores at the same time, increasing overall speed for programs that support multithreading or other parallel computing techniques. Manufacturers typically integrate the cores onto a single integrated circuit die or onto multiple dies in a single chip package. The microprocessors currently used in almost all personal computers are multi-core.