Asia: HCM city Europe: London Africa: Nothing North America: Washington D.C South America: Don't know Oceania: Australia Antartica: Polar bears
You can't fit a continent inside a city
North America, Mexico City has the largest population but I'm not sure about area wise
Milwaukee is the city in Wisconsin with the largest population.
California, who has a population of 37,691,912.
Lagos, Nigeria is the largest city on the African continent with a population of just over eight million people.
Berlin is the largest city in Germany with a population of 3,275,000.
Philadelphia with a population of 1,448,394 has the largest population.
Milwaukee is the city in Wisconsin with the largest population.
There are no cities on the continent of Antarctica. There are research stations, and there are times when the largest station is McMurdo Station with a transient population of about 1,000 souls.
Mexico City (population: 21,163,226)
By population or area? If population, and you are prepared to use Wikipedia as a source, which you probably shouldn't, London or Paris. This differs by your definition of city, and where you draw city limits.
Sydney is Australia's largest city, with a population of about 4,297,100. It is not the capital city.