GNOME Settings Daemon (gnome-settings-daemon) is an open source and free software project that has been designed from the offset to act as a daemon for handling the session settings of the GNOME desktop environment. It’s architecture comprises of plugins.

The GNOME Settings Daemon program is a core and essential component of the GNOME desktop environment, without which it is humanly impossible to handle a GNOME session and all the settings generated by other core components and applications.

The software is a simple daemon that runs in the background. Because it is distributed as a core component of the GNOME desktop environment, it cannot be used for any other open-source desktop environment. However, it is heavily also used by the Ubuntu Linux operating system to save its session settings under the Unity desktop environment.

The GNOME Settings Daemon package is required by many important GNOME applications, such as GNOME Shell, GNOME Control Center, GNOME Tweak Tool, and GNOME Disk Utility. Also, third-party applications, such as the Ubuntu One GNOME client, use the GNOME Settings Daemon program to save settings.

The program is written in the C programming language and it is automatically installed along with each fresh installation of the GNOME desktop environment. It is also available for download as a standalone package (gnome-settings-daemon), deployable on any GNU/Linux distribution.