Sempron has been the marketing name used by AMD for several different budget desktop CPUs, using several different technologies and CPU socket formats. The Sempron replaced the AMD Duron processor and competes against Intel's Celeron series of processors. AMD coined the name from the Latin semper, which means "always", to suggest the Sempron is suitable for "daily use, practical, and part of everyday life".

The first Sempron CPUs were based on the Athlon XP architecture using the Thoroughbred or Thorton core. These models were equipped with the Socket A interface, 256 KiB L2 cache and 166 MHz Front side bus (FSB 333). Thoroughbred cores natively had 256 KiB L2 cache, but Thortons had 512 KiB L2 cache, half of which was disabled and could sometimes be reactivated with a slight physical modification to the chip. Later, AMD introduced the Sempron 3000+ CPU, based on the Barton core with 512 KiB L2 cache. From a hardware and user standpoint, the Socket A Sempron CPUs were essentially identical to Athlon XP desktop CPUs with a new brand name. AMD has ceased production of all Socket A Sempron CPUs.