The history of Panachaiki began in 1891, when Panachaikos Gymnastikos Syllogos (Pan-Achaean Gymnastic Club) was founded. In 1894, a rival sports club, Gymnastiki Eteria Patron (Gymnastic Company of Patras), was founded in Patras by former Panachaikos' members. It was only in 1923 that both clubs came to an agreement and decided to merge, forming Panachaiki Gymnastiki Enosi.
The football department was found in 1899 by the BritishArthur Morphy and the same year the football team of Panachaiki played its first friendly game against a team of British sailors (winning 4-2). During the next years, the first players of the football team were athletes from the Club's other departments, members of the British community of Patras and Italian emigrates.
Kostas Davourlis Stadium tickets sold-out, Panachaiki vs A.S. Rodos in 2009 for Gamma Ethniki.
The team's privately owned arena is the Kostas Davourlis Stadium, the capacity of which is 11.321 seats. Despite that Panachaiki has also been using the much bigger Pampeloponnisiako Stadium, the capacity of which is 23.588 seats.