Festival Het Accordeon was a music event with concerts focusing on the accordion that took place in Deventer and Arnhem. Education and participation were regular parts of the program.
From 1993 to 1997, the festival took place annually in Deventer. It was conceived and organized by theater agency John Karrenbeld. In 2000, the organization came into the hands of The Accordion Foundation. It became a biennial festival.
In 2016, Erica Roozendaal was the musical director of the – as it turned out, the last – festival. In 2021, the Foundation ceased to exist and the remaining funds were transferred to NOVAM, the Dutch Organization for Accordion and Mondharmonica.