Western Rus' may refer to:
- western regions of Kievan Rus', including:
- Halychian Rus', an East Slavic medieval state, centered in Halych
- Volhynian Rus', an East Slavic medieval state, centered in Volhynia
- Halych-Volhynian Rus', an East Slavic medieval state, uniting Halych and Volhynia
- Kingdom of Rus', an East Slavic medieval kingdom (Galicia-Volhynia)
- Turovian Rus', an East Slavic medieval state, centered in Turov
- Polotskian Rus', an East Slavic medieval state, centered in Polotsk
- several Slavic historical regions, including:
- White Rus', an East Slavic historical region
- Black Rus', an East Slavic historical region
- Red Rus', an East Slavic historical region
- Carpathian Rus', a historical region inhabited mostly by Rusyns (Rusynia)