Maryland participates in the Sister States program to foster international cooperation, commerce, and cultural exchange. Its sister states/regions include:
- **Anhui Province**, China - **Gyeongsangnam-do**, South Korea - **Jalisco**, Mexico - **Łódź Voivodeship**, Poland - **Rio de Janeiro**, Brazil - **KwaZulu-Natal**, South Africa
Additionally, Maryland cities have their own active sister city programs. For example, Baltimore maintains relationships with Rotterdam (Netherlands), Kawasaki (Japan), and Luxor (Egypt), among others.