Lappeenranta was originally formed around a headland pointing to lake Saimaa. In the 16th century, the market place moved from Lappee's old centre Kauskila to the current fortress headland. The first mention of Lapwes, as it was called, is in a privilege charter from 1542 that subjugated the market place under Viborg's authority.
The town was chartered in 1649 by Queen Christina of Sweden, legitimizing the trade in the then popular marketplace of Lapvesi. However, the parliamentary privilege charter and the coat of arms were attested in 1652 after the town layout by Erik Aspegren was affirmed. At the time, Lappeenranta was an important port for tar.
Between 1721 and 1743, Lappeenranta was the capital of Kymmenegård and Savonlinna province.
In 1741, the battle of Villmanstrand was fought between the Swedish and Russian armies in the Russo-Swedish War of 1741–1743. The battle ended in a Russian victory. The town was pillaged, wooden structures including the provincial chancellery were burnt and the ecclesiastical archives damaged.
The municipality of Lappee was annexed to Lappeenranta in 1967. Nuijamaa joined in 1989. During the financial downturn of 2009 and 2010, Joutseno and Ylämaa respectively merged into Lappeenranta.
The name Lappeenranta consists of the genitive of Lappee and the appellative ranta which means "shore". The history of Lappeenranta includes the rural municipality of Lappee and the hundred Lapvesi. The Swedish name Villmanstrand contains the words Wildman meaning "wildman" and strand also meaning "shore". The wildman is depicted on Lappeenranta's coat of arms
