Marjory Bell, a union that lasted until Florence's death in 1992. They had two sons: James Robert Hillier and William Wynship Hillier.

A resident of Princeton, New Jersey, Hillier died there on January 15, 2007, due to a stroke.

Honours

* In 1950, the James Hillier Public School in Brantford, Ontario was opened.
* In 1960, he was awarded the Albert Lasker Award for Basic Medical Research.