Irving, TX - Official Website | Official Website, The City of Irving is an economic powerhouse in North Texas and is home to the region’s largest office park, where more than 10 percent of Fortune 500 companies are headquartered or have a significant presence. Irving is the 13th largest city in the state with 237,000 residents and the most diverse ZIP code in the country. Irving is the second city in the nation and the first in the State of Texas to receive the Malcolm Baldrige National Quality Award (2012) as well as the first municipality in.