The Airport Line is a route of the SEPTA Regional Rail commuter rail system in Philadelphia, Pennsylvania, which officially runs between Philadelphia International Airport through Center City to Temple University station. In practice, however, only a few trains originate or terminate at Temple University; most are through routed with lines to the north after leaving the Center City Commuter Connection. Half of weekday trains are through routed with the Warminster Line, with the other half of weekday trains through routed with the Fox Chase Line. All weekend and holiday trains are through routed with the Warminster Line and terminate either in Warminster or Glenside.

The SEPTA Regional Rail system is a commuter rail network owned by SEPTA and serving the Philadelphia metropolitan area. The system has 13 branches and more than 150 active stations in Philadelphia, Pennsylvania, its suburbs and satellite towns and cities. It is the sixth-busiest commuter railroad in the United States, and the busiest outside of the New York, Chicago, and Boston metropolitan areas. In 2016, the Regional Rail system had an average of 132,000 daily riders and 118,800 daily riders as of 2019.