NexGen, Inc. was a private semiconductor company based in Milpitas, California, that designed x86 microprocessors until it was purchased by AMD in 1996. NexGen was a fabless design house that designed its chips but relied on other companies for production. NexGen's chips were produced by IBM's Microelectronics division in Burlington, Vermont alongside PowerPC and DRAM parts.

The company was best known for the unique implementation of the x86 architecture in its processors. NexGen's CPUs were designed very differently from other processors based on the x86 instruction set at the time: the processor would translate code designed to run on the traditionally CISC-based x86 architecture to run on the chip's internal RISC architecture. The architecture was used in later AMD chips such as the K6, and to an extent most x86 processors today implement a "hybrid" architecture similar to those used in NexGen's processors.

It went public in 1994, and was bought by AMD in 1995 for $850M. The technology forms the platform architecture for all of AMD's current microprocessors. It was an unusual start-up in its time as the original funding came from corporate investors, Compaq and Olivetti, joined in a later round by venture capital firm Kleiner Perkins.