In computing, C strings are strings stored as one-dimensional character arrays in the C and C++ programming languages. In C, they are simply called "strings," while in C++ they are called "C strings" to differentiate them from STL (ANSI standard C++) strings. C strings are distinguished by the fact that they are terminated with a null character ('\\0'). This null-termination characteristic has historically created security problems related to the length of the string.

A number of stringed instruments, including the viola and cello, have a string that, when played open, produces the note C. This is usually referred to as the C string.