Apple has included a new wallpaper with the release of macOS Sonoma 14. You can download the official wallpaper here.
The default wallpaper is a colorful abstract that looks great on any device. It's offered in HEIC format which includes both light and dark versions. We've also bundled JPG versions of the wallpaper for your convenience.
You can easily add downloaded wallpapers to your Mac via System Settings (Apple menu). Here are instructions on how to set your desktop wallpaper on Mac... ● How to Change Wallpaper on Mac
Apple has also released new wallpaper for iOS 17 and iPadOS 17. Those are specifically designed for iPhone and iPad; however, you can also use them on devices that run a different OS.
UPDATE: Apple has added a beautiful new "Sonoma Horizon" landscape desktop wallpaper in sixth beta of macOS Sonoma 14 featuring the Sonoma Valley in California, USA. We've added it below and to the zip file of all the new wallpapers.