The Rogožarski SIM-XII-H (Serbian Cyrillic:Рогожарски СИМ-XII-Х) was a Yugoslav trainer single-engine floatplane, with two floats designed in 1938.

Since it was not possible to make a simple modification (adaptation of existing aircraft SIM-X) for installation of EDO floats, chief designed Sima Milutinović fitted the plane with a more powerful engine Walter Major 6 190 hp, leading to an increase in aircraft size.

After the flight tests had achieved satisfactory results, the first batch of aircraft was ordered, which were delivered in mid-1939.

[3] Aircraft SIM-XII-H, a supported two-seat high-flying plane, with engine Walter Major 6 (190 hp), of predominantly wooden construction, with an elliptical cross-section of fuselage entirely made of wood and covered with plywood, wings as the supporting structure made of wood covered with fabric, with rounded ends.

When the approval was given, the floats were installed into new planes, so the aircraft in the second series were enabled for use before the war broke out.