Is this true?
If Sydney was in the US, it would be their 2nd largest city after New York (8.2 million).
If Melbourne (3.7 million) were in the USA it would be their 3rd
largest city after Los Angeles (3.8 million).McCrindle Research, Who We Are: A Statistical Snapshot of 21st Century Australia. (PDF)
The short version: Yes.
The long version: Yes. Sydney’s population is currently 4,284,379, which places it firmly in second place in the United States’ most populace cities, with Melbourne just behind Los Angeles’ 3,849,378 with a grand total of 3,806,092.