- Delta Air Lines is a major American airline that is headquartered in Atlanta, Georgia. It is one of the largest airlines in the world and operates a vast network of domestic and international flights. Delta operates over 5,400 flights daily and serves more than 300 destinations in over 50 countries. It is a founding member of the SkyTeam alliance and has codeshare agreements with various other airlines. Delta offers various cabin classes, including Delta One, First Class, Delta Comfort+, and Main Cabin. The airline is known for its customer service, extensive route network, and loyalty program called Delta SkyMiles.