Founded in 1956 and headquartered in Washington, DC, Sister Cities International is a nonpartisan nonprofit serving as the national membership organization for 467 U.S. sister cities, counties, and states with 1,800 partnerships in 138 countries on six continents. It’s the largest citizen diplomacy network in the world, which serves as a hub for institutional knowledge and best practices in the field of citizen diplomacy and unites tens of thousands of citizen diplomats and volunteers.

Sister Cities International creates relationships based on cultural, educational, information and trade exchanges, creating lifelong friendships that provide prosperity and peace through person-to-person “citizen diplomacy.” It continues to expand its reach to new and emerging regions of the world. Today, it dedicates a special focus on areas with significant opportunities for cultural and educational exchanges, economic partnerships, and humanitarian assistance.

Established: 1956

Members: 2,267

Member since: 2002

Website: https://www.sistercities.org/