MD Helicopters, LLC. is an American aerospace manufacturer. It produces light utility helicopters for commercial and military use. The company was a subsidiary of Hughes Aircraft until 1984, when McDonnell Douglas acquired it and renamed it McDonnell Douglas Helicopter Systems. It later became MD Helicopters in 1999 after McDonnell Douglas merged with Boeing.

The MD Helicopters MD 500 series is an American family of light utility civilian and military helicopters. The MD 500 was developed from the Hughes 500, a civilian version of the US Army's OH-6A Cayuse/Loach. The series currently includes the MD 500E, MD 520N, and MD 530F.