Donald Trump with Paris and Nicky Hilton in 2001. Photo / Getty Images.Paris laughed nervously when quizzed about her decision in the polling booth, but she did eventually respond, "Yes".
This decision puts her at odds with Hollywood's liberal elite, which overwhelmingly rallied for the Democratic candidate.
Earlier this month, Paris refused to say if she voted for Trump when questioned by a TMZ videographer.
She is a family friend of the politician, who defeated Hillary Clinton in a historic race to the White House last week.
Trump claimed he first met Paris - a friend of his daughter Ivanka's - when she was 12 years old, and described her as "beautiful".