Yes, Delta Air Lines will generally transfer your checked luggage automatically to your final destination if all your flights are booked on the same itinerary (PNR). This applies to both domestic-to-domestic and domestic-to-international connections. However, there is a major exception: International-to-Domestic connections upon arrival in the U.S. If you are flying from an international city (like London) to Atlanta and then connecting to a domestic city (like Orlando), you must claim your bag after clearing immigration, walk it through Customs, and then place it on the "Baggage Re-check" belt just outside the customs hall. In 2026, Delta's app offers a "Track My Bags" feature that sends real-time notifications to your phone when your bag has been scanned onto your connecting flight, providing peace of mind during tight transfers. If you have booked two separate tickets on different airlines, you will likely need to claim and re-check your bags manually.