The Royal Air Force Long Service and Good Conduct Medal is a medal awarded to regular members of the Royal Air Force in recognition of long service. It was instituted by King George V in 1919, the year following the establishment of the world's first independent air force. At first, the medal was awarded to Regular Force non-commissioned officers and airmen of the Royal Air Force. The award criteria were later relaxed to also allow the award of the medal to officers who had served a minimum period in the ranks before being commissioned. Since 2016, it is awarded to all regular members of the RAF, including officers who had never served in the ranks.

The Army Long Service and Good Conduct Medal was instituted by King William IV in 1830. The medal remained in use for 100 years, until it was replaced by the Medal for Long Service and Good Conduct (Military) in 1930. During that time the reverse of the medal remained virtually unchanged, while the design of the obverse was altered during the reigns of Queen Victoria, King Edward VII and King George V.