For Updated ONE UI 5, check this tutorial.
- Choose your font in .ttf and install it with Zfont 3 on your phone by following this tutorial.
- Download Apk extractor, open it and search for the apk of your font, then click on it to extract the apk.
- Finally sideload the apk of your font with Easy fire tool on your Galaxy Watch Wear OS by following this tutorial: https://ladypinkilicious.com/2022/11/11/how-to-install-hello-kitty-watch-faces-on-galaxy-watch-4-5-wear-os/
- Once you’re done to sideload the font in your Galaxy Watch, go in your settings/display/font
- Then select SamsungSans
- Enjoy! If you’re looking for the cutest fonts, check Ada font or Gs font.