Acordding to Eric W. Robinsons's Democracy Beyong Athens; Popular Government in the Greek Classical Age, many cities had. He divides in two groups:

Had democracy at some point with high degree of certainty:

Syracuse, Acragas, Gela, Himera, Leontini, Selinous, Messana, Croton, Caulonia, Rhegium, Thurii, Corcyra, Epidamnus, Cyrene, Achea, Argos, Corinth, Elis, Mantinea, Phlius, Zacynthus, Megara, Plataea, Thebes, Abdera, Teos, Amphipolis, Iasus, Cnidus, Ephesus, Erythrae, Hestiaea, Miletus, Paros, Rhodes, Eretria, Mytilene, Samos, Thasos, Byzantium, Calchedon, and Cherson

With low degree of certainty:

Camarina, Heraclea, Sicyon, Leucas, Thessaly, Cyme, Aphytis, Cos, Olbia, and Istrus

He explains one by one in his book