Socket S1 is the CPU socket type used by AMD for their Turion 64, Athlon 64 Mobile and later Sempron processors, which debuted with the dual core Turion 64 X2 CPUs on May 17, 2006. Socket S1 has 638 pins, and replaces the existing Socket 754 for laptops. It has been expected that desktop motherboards will appear using Socket S1, much as boards using the Pentium M's Socket 479 are on the market.

Socket S1 includes support for dual-channel DDR2 SDRAM, dual-core mobile CPUs, and virtualization technology, to compete with the mobile Intel Core 2 processor series.

Socket S1 is a part of AMD's current generation of CPU sockets, along with Socket F (servers) and Socket AM2 (desktop).