Nimipaivat.com

Ilkka 

“Ilkka is a Finnish male first name. The name is known as a symbol of Finnish freedom and determination. This reputation was given to the name by Jaakko Ilkka, a leader of the Ostrobothnian peasant rebellion known as the ‘Nuijasota’ (the Club War). Ilkka was added to the name day calendar in 1929, but its exact origin is unknown.

By the end of 2019, the name Ilkka had been given to 17,157 Finnish men and fewer than 15 women.

Ilkka is also a Finnish surname.”