The OZ-06MS Leo is a mass-produced general purpose mobile suit introduced in the TV anime Mobile Suit Gundam Wing.

The OZ-06MS Leo was the first mass-produced MS developed by OZ, based on the blueprints of the first combat MS in A.C. history, the "OZ-00MS Tallgeese". The engineer in charge of the development was OZ's Seis Clark. Unlike the Tallgeese, which was so focused on performance that its design disregarded safety and could not be piloted by ordinary people, the Leo was designed to be piloted by normal soldiers, and focused on ease of production and versatility. This was also due to OZ and the United Earth Sphere Alliance (UESA) being at odds with the space colonies at the time of its development, and priority was placed on production and its role as a threatening machine rather than excessive performance. As a result, it was simplified and downsized to a level where it could be mass-produced. The back, front and rear of both shoulders, and the sides of the thighs have mechanisms for attaching optional equipment, and by changing its equipment, the Leo can respond to a variety of battlefields. In addition, a performance index for mobile suit, the "Ability Level", was established by setting each of the Leo's performance values at 100 and evaluating the performance of other machines against them.