Harry James Duynhoven (born 1955) is a New Zealand politician and member of the New Zealand Labour Party.
He was the mayor of the city of New Plymouth and surrounding districts from 2010–2013.
He was a Member of Parliament for the New Plymouth electorate from 1987–1990, from 1993–2003, and again from 2003–2008.
Duynhoven was elected as Mayor of New Plymouth in October 2010.
Since leaving office in October 2013, he is currently a district councillor representing the New Plymouth City ward and a board member on Taranaki's district health board.