KaOS is an Arch-based Linux distribution built around the latest version of the KDE desktop environment. It includes LibreOffice and other popular software applications based on the Qt toolkit.

The first version of KaOS was released as "KdeOS" in 2013. To prevent confusion between the distribution's name and the desktop environment KDE, the name was changed to "KaOS" in September 2013.

KaOS is distributed via an ISO image, and exclusively supports 64-bit x86 processors.

KaOS is a desktop rolling release, built from scratch with a very specific focus. The focus on one desktop environment (KDE Plasma 6), one toolkit (Qt), one architecture (x86 64), with an emphasis on evaluating and selecting the most suitable tools and applications.

The default applications include:

Phoronix wrote in 2016, "Overall, I was quite pleased with it for being a niche distribution. KaOS was easy to install and was quickly running on a bleeding-edge KDE Plasma 5 stack. Overall, it was a fun and pleasant few hours spent with KaOS."

FossMint stated in 2017, that KaOS "is a modern, open-source, beautifully designed, QT and KDE-focused Linux distro. It is a rolling release that ships with KDE Plasma as its default Desktop Environment, uses Pacman as its package manager, and has a 3-group structure repository on GitHub." and "The fact that it is a rolling release means that you will never need to worry about future updates the moment you have a version installed like in the case of Ubuntu and the like where you would need to consider whether to perform a clean installation of another “major version” or not."

Hectic Geek reviewed KaOS in 2014, and wrote that the distribution was not very fast, but included all necessary applications.