The 59-year-old has penned a one-year deal with Persepolis.
Oenning began his coaching career with FC Nürnberg in 2008 and has also worked as the head coach of Hamburger SV.
Persepolis, the most decorated Iranian club in the league, finished third last season and missed a place in the Asian competition.
The Reds opened the new Iran Pro League (IPL) season with a 1-1 draw against Fajr Sepasi and then defeated Sepahan 1-0.