The eastern sector of the Alps has been heavily influenced by post-collisional indentation tectonics since the Miocene. In current times Adria-Europe convergence, albeit slow, is accommodated and distributed across several faults in the Eastern Alps. Instrumental seismicity records cover only a portion of the timescale from what can be considered seismogenic active faulting and paleoseismological approaches are not always applicable to date fault activity. We apply optically stimulated luminescence (OSL) and electron spin resonance (ESR) dating to fault gouges to constrain which portions of the Periadriatic Fault System (PAF), Lavanttal Fault, and Šoštanj Fault have experienced seismotectonic deformation during the Quaternary. Our results indicate that the PAF was active during the Quaternary with maximum ages given by ESR dating ranging from 899 ± 67 to 305 ± 25 ka, and minimum ages from the saturation of OSL signals of 179 ± 13 to 62 ± 4 ka. In the case of the Lavanttal Fault, the measured samples show saturation of the ESR signals with minimum ages for seismogenic activity ranging from 863 ± 41 to 2151 ± 323 ka. For the Šoštanj Fault, a maximum age of activity of 30 ± 4 ka is given by OSL dating, suggesting that it has been more seismically active during the Quaternary than the other two studied faults. In general, our results show the utility of ESR and OSL dating in identifying periods of fault activity where other approaches fail to assess it.