The Rogožarski SIM-XI (Serbian Cyrillic: Рогожарски СИМ-XI) was a single-seat, single-engine trainer monoplane built in the Kingdom of Yugoslavia in 1938.

When examining the earlier SIM-X, it was observed that it had aerobatic characteristics, so the factory management decided to install a more powerful engine with a carburetor for inverted flights, reduce the lower wing struts, reduce the wing area and make the construction more flexible to give a more aerobatic aircraft.

[3][4] The Rogožarski factory designed the SIM-XI with the intention of keeping resources of fighter aircraft as part of standard air force armaments arsenal while enabling YRAF pilots to continue aerobatics training on cheaper aircraft without affecting the quality of the training.

During the first international aviation exhibition in Belgrade, the SIM-XI performed a series of highly acclaimed aerobatic flights, confirming the fact that it belonged to a group of the best aerobatic aircraft at the time, which was used another credit to acclaimed engineer Sima Milutinovic, to the Rogožarski factory and the Yugoslav aviation.

[6] The Croats used it until 19 December 1943, for glider towing, until partisans destroyed it between the villages of Progar and Boljevci when a Croatian pilot landed in order to reattach and lift the hook that had fallen off.