Catharina Isabella "Ien" Dales (18 October 1931 – 10 January 1994) was a Dutch politician and social worker. Born in Arnhem, she received a degree in education from the University of Amsterdam and worked in social services before her career in politics. She became a member of the Labour Party (PvdA) in 1968 and was appointed State Secretary for Social Affairs and Employment in the Van Agt II cabinet, a position that she held between 1981 and 1982. Dales was a member of the House of Representatives between 1981 and 1987 and mayor of Nijmegen between 1987 and 1989. She was the Minister of the Interior in the Lubbers III cabinet from 1989 and 1994.