C shell（csh）是Unix shell的一种，由比尔·乔伊在BSD系统上开发。C shell脱胎于Unix第六版的/bin/sh，也是Bourne shell的前身。这种shell的语法类似于C语言，与Bourne shell相比，C shell有不少特别的功能，比如aliases（别名）、command history（命令的历史）。目前C shell已不再被广泛使用，后继者包括Tenex C shell（tcsh）、Korn shell（ksh）、GNU Bourne-Again shell（bash）。

The C shell (csh or the improved version, tcsh, on most machines) is a Unix shell that was created by Bill Joy while he was a graduate student at University of California, Berkeley in the late 1970s. It has been distributed widely, beginning with the 2BSD release of the BSD Unix system that Joy began distributing in 1978. Other early contributors to the ideas or the code were Michael Ubell, Eric Allman, Mike O'Brien and Jim Kulp.