Short and sweet – most populous one syllable cities – UPDATED

Seoul – Source: alumni.wustl.edu

Here is my list of the largest single syllable cities (in English) in the world by rounded off metro population (when known).

• Seoul, South Korea – 24,200,000
• Rome, Italy – 3,700,000
• Prague, Czech Republic – 2,300,000
• Leeds, UK – 2,300,000 (thank you, Warren)
• Perth, Australia – 2,000,000
• Minsk, Belarus – 1,850,000
• 

  Perth – Source: perth-wa.net.au

  Lille, France – 1,240,000

• Omsk, Russia – 1,140,000
• Fez, Morocco – 1,110,000
• Perms, Russia – 1,060,000
• Qom, Iran -1,050,000
• Hims, Syria – 1,050,000
• Nice, France – 1,000,000
• Bern, Switzerland – 660,000
• Cork, Ireland – 518,000
  

  Cork – Source: glogster.com

• Van, Turkey – 500,000
• Flint, Michigan, USA – 426,000
• Sparks, Nevada, USA – 425,000 (with Reno)
• Kursk, Russia – 415,000
• Split, Croatia – 350,000
• Bonn, Germany – 325,000
• Brest, France – 300,000
• Reims, France – 292,000
• Mau, India – 279,000
• Durg, India – 268,000
  

  Durg – Source: quickbooker.com

• Brugge, Belgium – 255,000
• Mage’, Brazil – 244,000
• Kiel, Germany – 240,000
• York, United Kingdom – 202,000
• Mainz, Germany -200,000
• Cairns, Australia – 153,000
• Neuss, Germany – 151,000
• York, Ontario, Canada – 150,000 (part of larger Toronto metro area)
• Slough, United Kingdom – 142,000
• Nimes, France  -140,000
• Ulm, Germany – 123,000
  

  Ulm – Source: ysfine.com

• Furth, Germany – 116,000
• Lund, Sweden – 110,000
• Moers, Germany – 105,000

Sources: en.wikipedia.org and http://www.sporcle.com