The Lockheed L-649 Constellation was the first real civilian version of the Lockheed Constellation line, as the Lockheed L-049 Constellation was a simple redesign from the military Lockheed C-69 Constellation. The L-649 was planned to be the new standard version of the Constellation, but the L-749 Constellation, a co-jointly produced improved derivative, was chosen over the L-649 by most airlines. Most of the few L-649 aircraft built were delivered and operated by Eastern Air Lines.

The Lockheed Constellation ("Connie") is a propeller-driven, four-engined airliner built by Lockheed Corporation starting in 1943. The Constellation series was the first pressurized-cabin civil airliner series to go into widespread use. Its pressurized cabin enabled commercial passengers to fly well above most bad weather for the first time, thus significantly improving the general safety and ease of air travel.