Montreal's Jardin finished 10th Monday's semifinal, while Cheverton, of Lachine, Que., was 11th.
It was still an impressive Olympic debut for the pair, who looked strong in the preliminary swim.
Jardin was sixth fastest in the preliminaries with a time of one minute 57.92 seconds, while Cheverton, of Lachine, Que., was ninth in 1:58.11.
Both swimmers were in the same heat, ranking fourth and fifth respectively.
"It's my best time in the morning by a lot," said Jardin, whose aunt Anne Jardin swam at the 1976 Olympics in Montreal. "I was nervous but I knew my race plan and I stuck to what I had to do."
In the women's 200 individual medley, Calgary's Erica Morningstar missed a semifinal berth by 0.06 seconds, finishing 17th in 2:14.32.
In the men's 200 butterfly, David Sharpe of Halifax ranked 31st overall.
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