World's Most Populous Capital City: Tokyo

Tokyo, Japan is the capital city with the largest population.

• City proper (23 Special Wards): ~9.7 million.
• Metropolitan Prefecture (Tokyo Metropolis): ~14 million.
• Greater Tokyo Area (Kanto region): **~37–38 million** — world's largest urban agglomeration.

Runners-up (metro): Jakarta (~34M), Delhi (~32M), Seoul (~26M), Mexico City (~22M), Manila (~24M), Shanghai (~29M).

Tokyo combines extreme density with extraordinary order, transit, safety, and economic output (~$2T GDP).