Every theme ships with its own set of backgrounds, and you can add extras of your own in ~/.config/omarchy/backgrounds/[theme]. If you want to add an extra background image to, say, the nord theme, you just put the file in ~/.config/omarchy/backgrounds/nord.

You can do this most easily by going to Install > Style > Background in the Omarchy Menu. That’ll bring up the folder where the backgrounds for that theme is stored. Hit Super + Shift + F to start another file manager, find your background, copy it over. Now it’ll be included in the choices of backgrounds you can select between using Super + Ctrl + Space.

Backgrounds can be videos as well as stills. Drop an mp4, m4v, mov, webm, mkv, or avi file in the same folder and it appears alongside the images, playing on a loop. Only your first monitor’s wallpaper plays a video’s sound track, through the default audio output at the system volume, and the lock screen stays silent. Playback stops on its own whenever nothing can see it — while a fullscreen window covers that monitor, while the screensaver is up, and once a locked screen has gone dark — but a video wallpaper still costs far more power than a still one, and each monitor decodes its own copy.

You can find a huge collection of cool curated backgrounds on https://github.com/dharmx/walls.