In her first Olympics, Canadian skip Jones sealed a 6-4 win over Britain with the final stone of the match. It was a just reward for the Canadians who had the contest under control after taking a 3-0 lead following the first two ends.
"I have all the confidence in the world in Jen making those shots for the win," said Canada's Kaitlyn Lawes. "She nailed it yet again."
Sweden, seeking a third successive gold, survived a scare to edge Switzerland 7-5 in the other semifinal.
Switzerland led 5-4 with eight of the 10 ends completed and could have stolen victory with the last stone but skip Mirjam Ott agonisingly failed to take the chance.
"The only thing we could do was just sit there and hope that the rock was heavy, and it was," said Sweden's Maria Wennerstroem.
Canada are the first women's team to make it through an Olympic round robin without a loss and will be confident of taking revenge on the Swedes in Thursday's final.
British skip Eve Muirhead, who had kept her team in contention with an accurate last stone. said she was "gutted" by the defeat.
"We got off on the back foot with two points (against) in the first end, but I knew that playing Canada would never be easy," she said.
Britain will play for bronze against the Swiss on Thursday.
"We will just take a little bit of time tonight to get over it and make sure we are emotionally ready for the next game, as we don't want to leave the Games empty-handed," said Britain's Anna Sloan.
(Writing by Keith Weir, editing by Robert Woodward)
