Apollon, God of the sun and well-being and Hera, mother of all Gods, were worshipped here in temples, ruins of which still remain nowadays. The first written reference to the water of Loutraki is in the «Hellenica» by the Athenian historian Xenophon (431-351 B.C.). He referred to Thermes (the ancient name of Loutraki) mentioning that Agisilaos, King of Sparta, had camped there during the Corinthian war (395-387 B.C.). His description combined with historical facts and archaeological findings, confirm that this information refers to the city of Loutraki. The area also known as Peraea (Peraea means beyond Corinth), was colonized by the Corinthians in 750 BC.
There are also historical references that ,in 146 BC, when the city came under domination of the Romans, General Sulla, was cured by its spa water and thus its secrets were disseminated throughout the entire Roman world.
Moreover, plenty of churches built during the Byzantine era indicate the importance of the city and its historical development through the ages. Loutraki had a key role during the Greek Revolution in 1821 due to its geographical position, as many battles took place there. The most famous battle was against Dramalis (September 25th-27th, 1822) where Greek troops obliterated Dramalis’ forces - the victorious battle strongly contributed to the results of the revolution: the liberation and the establishment of the Greek State.
In 1928 Loutraki was completely destroyed by earthquake and rebuilt. A large park was created by reclaiming sea area using the rubble of the fallen houses. Another strong earthquake hit the area in 1981 with less destructive effects.