Charles James Mayer, PC (born April 21, 1936) is a Canadian businessman and former federal Minister of Agriculture.
He was educated at the University of Saskatchewan and became an agrologist and farmer.
Politically active, Mayer was president of the Manitoba Beef Growers Association before entering the House of Commons of Canada as a Progressive Conservative Member of Parliament in 1979.
In early 1993 he was promoted to Minister of Agriculture and was retained in that position during the short-lived government of Mulroney's successor, Kim Campbell.
He endorsed Lawrence Toet when he attempted to be the Conservative candidate in the 2023 Portage—Lisgar federal by-election.