At the start of the Korean War, the Mustang was the main fighter of the United Nations until jet fighters such as the F-86 took over this role; the Mustang then became a specialized fighter-bomber.
Končni različici, P-51D in P-51K, sta bili opremljeni z motorjem Packard V-1650-7 (motor je po licenci izdelovana različica dvostopenjskega dvohitrostnega prisilno polnjenenega motorja Rolls-Royce Merlin) in oboroženi s po šestimi 12.7 mm M2 Browningovimi strojnicami.