Cornelius "Kees" Claudius Henricus van Ierssel (Dutch pronunciation: [k?r'ne?lij?s 'ke?s 'kl?udij?s '??nrik?s f?n 'i?rs?l]; born 6 December 1945, Breda) is a Dutch former footballer who played as a defender.
During his club career he played for FC Twente from 1969 to 1979.
He earned 6 caps for the Netherlands national football team, and was part of the squad that finished as runners-up in the 1974 FIFA World Cup.