Delta Airlines Phone Number, typically referred as Delta. It is a major American Airlines, its headquarters is in Atlanta, Georgia. The airlines in total operates over 5,400 flight daily and serves as an extensive Domestic and International network including 304 destination within 52 countries on six continents. Delta is also a Founding members of the Sky Team Airlines Alliances. Among the five remaining legacy carriers Delta Airlines is the sixth oldest operating airline by foundation date and also the oldest airlines still operating in united States.