As a census-designated place, Annandale does not maintain its own municipal sister city agreements. However, it operates under the jurisdiction of Fairfax County, which holds a highly relevant international partnership:
* **Songpa-gu, Seoul, South Korea**: Given Annandale's status as a major hub of Korean-American culture, Fairfax County's sister city relationship with this vibrant district of Seoul carries special resonance for the local community.
