There are already object-based language concepts involved in the design of a more typical operating system such as Unix.
While a more traditional language like C does not support object-orientation as fluidly as more recent languages, the notion of, for example, a file, stream, or device driver (in Unix, each represented as a file descriptor) can be considered a good example of objects.
Historically, the object-oriented design principles were used in operating systems to provide several protection mechanisms.
[1] Protection mechanisms in an operating system help in providing a clear separation between different user programs.
It also protects the operating system from any malicious user program behavior.