De Leeuw was born in Orange, California, USA. Her mother is Dutch and her father had dual US/Dutch citizenship. Dianne de Leeuw skated for the Netherlands, despite having been born and having spent most of her youth in the U.S.
She was voted the female athlete of the Netherlands in 1975 by winning the World Ice Skating Championship. She was known for her classic skating style. She was also flag carrier at the 1976 Winter Olympic Games for the Netherlands.
Following her retirement from skating, she became a coach. She has coached at the Westminster Ice Palace in Westminster, California. She married her former coach Doug Chapman and they coach skating together.