Delta Air Lines is an airline.
Delta Air Lines , Inc. ( `` Delta '' ; ) is a major American airline , with its headquarters and largest hub at Hartsfield -- Jackson Atlanta International Airport in Atlanta , Georgia . The airline along with its subsidiaries and regional affiliates operate over 5,400 flights daily and serve an extensive domestic and international network that includes 319 destinations in 54 countries on six continents , as of October 2016 . One of the five remaining legacy carriers , Delta is the sixth-oldest operating airline by foundation date , and the oldest airline still operating in the United States . In 2013 , Delta Air Lines was the world 's largest airline in terms of scheduled passengers carried ( 120.6 million ) , and the second-largest in terms of both revenue passenger-kilometers flown ( 277.6 billion ) and capacity ( 4.4 billion ASM/week ; March 2013 ) .