Socket 423 is a 423-pin CPU socket used by Intel's first generation of Pentium 4 processors based on the Willamette core.

This socket was short-lived, as it became apparent that its electrical design proved inadequate for raising clock speeds beyond 2.0 GHz.

Intel produced chips using this socket for less than a year, from November 2000 to August 2001.

All processors using this socket have a locked multiplier, meaning that they are not overclockable unless the front side bus frequency is increased.

Doing this, however could push other buses out of spec, causing erratic behaviors such as system instability and premature failure.