i know of livorno, celtic, rayo vallecano, union st gilloise, standard liege, red star paris, bologna (maybe?) and the better version of st pauli babelsberg 03
liverpool, man utd and basically everyother major football club have some socialist history due to it being a working class sport, but it seems that is just history now. the big clubs are all moneygrubbing bastards
Replied to another comment about this as well, but Union Berlin / its supporters are not left wing. If anything, they tend to be a bit to the right (although nominally they are apolitical).
This is true of every club in Germany and is not indicative of its political leanings.
That’s disappointing, but considering AfD’s popularity in the former East Germany, maybe not that surprising. Maybe I shouldn’t expect that just because a club is from a formerly communist country, their supporters would be left-wing (Red Star Belgrade for example).
East Germany got fully undermined by western neo-nazis especially the sport scene which was the only public space not destroyed by treuhand. The majority of institutions there are openly controlled by the fash (although there is still the pretence in the west). Take the police of Dessau-Roßlau, for example, who regularly kidnaps and lynches foreign students and non-White individuals; I believe they just did it to a Sinti person yesterday.