NESticle was a popular NES emulator for DOS, created by Bloodlust Software (the team that also created Genecyst).

NESticle offered its initial release as NESticle v0.2 on April 3rd, 1997. The program originally ran under DOS and Windows 95, offering few features and only supporting a handful of games. It was one of the first freeware NES emulators, and quickly became more popular than shareware rivals such as iNES. Within a few weeks the program had become considerably more robust, and could play the majority of available NES ROMs. It was widely considered the best NES emulator available.

August 1998 saw the final NESticle vx.xx release and with it the end to support and further updates. Bloodlust continued to work on Genecyst, an emulator for the Sega Genesis.

NESticle eventually became obsolete as other emulation projects continued to develop and improve. However, it was a major step in the evolution of console emulation, noted for the public introduction of save states, automatic frameskipping, in-game movies and for being completely free.

The current webpage for NESticle is hosted on Zophar's Domain.

The name NESticle is a portmanteau of NES, the console it emulates, and testicle.