Houston Intercontinental Airport Surpasses O’Hare as United’s Largest Hub CheapOair Staff May 27, 2011 general More United flights operate out of Houston than anywhere else The ongoing merger of operations between United and Continental Airlines means that Chicago’s O’Hare International Airport has been dethroned as United’s largest hub. That title now belongs to Houston George Bush Intercontinental Airport. Houston’s 630 daily United flights now narrowly eclipses O’Hare’s 607. Despite losing the United crown, O’Hare remains the busier of the two airports. Once number one in the world, O’Hare is now fifth busiest airport on the globe. Houston comes in at a distant number 25 in terms of air traffic. Source: USA Today