Key Takeaways Houston (population 2.3 million city / 7.3 million metro) is significantly larger than Dallas (1.3 million city / 7.1 million metro) Houston is the 4th largest city in the US; Dallas is the 9th Houston covers 670+ square miles vs Dallas at 385 square miles — Houston is nearly twice the physical size Houston has more international diversity, NASA, the Texas Medical Center, and a larger port economy Dallas has a stronger public transit system (DART), more corporat