The following is a list of sister cities of Seoul, and the date of commencement.

• Taipei, Taiwan
  • March 23, 1968
• Ankara, Turkey
  • August 23, 1971
• Honolulu, USA
  • October 22, 1973
• San Francisco, USA
  • May 18, 1976
• Sao Paulo, Brazil
  • April 20, 1977
• Bogota, Colombia
  • June 14, 1982
• Jakarta, Indonesia
  • July 25, 1984
• Tokyo, Japan
  • September 3, 1988
• Moscow, Russia
  • July 13, 1991
• New South Wales, Australia
  • November 8, 1991
• Paris, France
  • November 12, 1991
• Mexico City, Mexico
  • October 5, 1992
• Beijing, China
  • October 23, 1993
• Ulaanbaatar, Mongolia
  • October 6, 1995
• Hanoi, Vietnam
  • May 1, 1996
• Warsaw, Poland
  • June 20, 1996
• Cairo, Egypt
  • April 27, 1997
• Rome, Italy
  • March 18, 2000