The Hilary Weston Writers' Trust Prize for Nonfiction is a Canadian literary award, presented annually by the Writers' Trust of Canada to the best work of non-fiction by a Canadian writer.
First established in 1997, the award's original corporate sponsor was Viacom. Pearson Canada, the regional branch of an educational book publishing company, took over the award in 1999, and Nereus Financial, a stock brokerage, became the sponsor from 2006 to 2008. After Nereus dropped its sponsorship, the award had no corporate sponsor until 2011, when Hilary Weston (a philanthropist and former Lieutenant Governor of Ontario) was announced as the award's new sponsor.
Canada's most lucrative non-fiction prize, the winner receives a cash sum of and all finalists receive . Prior to Weston's patronage of the award, the prize would consist for the winner and for the finalists.
In 2023, the Writers' Trust introduced the Weston International Award, a prize which honours international non-fiction writers. Unlike the Canadian award, the international award does not release a list of finalists in advance of the winner announcement, and honours the writer for their overall body of work rather than an individual book.