Potaissa was a legionary fortress and later a city in the Roman province of Dacia, located in today's Turda, Romania.

The Dacians established a town that Ptolemy in his Geography calls Patreuissa, which is probably a corruption of Patavissa or Potaissa, the latter being more common.

The start of the Marcomannic Wars and murder of the governor Calpurnius Proculus led Rome to send the Legio V Macedonica from Troesmis to Potaissa around 168 AD to strengthen the north-western defenses of Roman Dacia.

They built their legionary fortress nearby on the "Cetate" Hill as their base It was used until 274 after which the legion was moved by Aurelian to Oescus on his withdrawal from Dacia.

The complete inscription is: "Imp(erator)/ Caesar Nerva/ Traianus Aug(ustus)/ Germ(anicus) Dacicus/ pontif(ex) maxim(us)/ (sic) pot(estate) XII co(n)s(ul) V/ imp(erator) VI p(ater) p(atriae) fecit/ per coh(ortem) I Fl(aviam) Vlp(iam)/ Hisp(anam) mil(liariam) c(ivium) R(omanorum) eq(uitatam)/ a Potaissa Napo/cam / m(ilia) p(assuum) X".