The roots of Espoo Day date back to several past decades when the city was celebrated at various village festivals and theme events. Officially, an event called Espoo Day was first held in 1992, which is the same year when Espoo celebrated its 20th anniversary as a city. The event was held on 27 August, which is the day when the founding document of Espoo Manor was signed in 1556.

Since 2010, the event has been celebrated every year on the last Saturday of August. Every year, Espoo Day features more than 150 events organised by residents, communities, companies and the city. In 2017, Espoo Day included more than 300 events and was celebrated for the entire weekend in honour of the centenary of Finland’s independence. Admission to Espoo Day events is always free of charge.