By Alan Baldwin
Hamilton, the 2008 champion, is the only man to beat the German this year and Canada offers the 26-year-old Briton -- second in the championship and 58 points behind Vettel -- one of his best opportunities to do it again.
In three appearances at the Circuit Gilles Villeneuve, Hamilton has been on pole position each time and triumphed twice.
He did it with clever tire strategy last year and that will the key again this time, now that the quicker-wearing Pirellis have replaced Bridgestone.
"I've always got on really well with the track, the layout seems to suit my driving style, and I won there last year from pole position.
"Our car should be well suited to this track; we have a great engine, the best KERS Hybrid system in the sport and excellent traction out of slow corners," added the Briton.
"All in all, it's set to be another good weekend for us. I'll be looking for a strong result on Sunday."
After collecting two drive through penalties in Monaco, one of them retrospective, and bad-mouthing the race stewards and rivals who came out worse from collisions with the McLaren, Hamilton has some fences to mend.
A good result in Canada, ironically the scene of one of his biggest gaffes in 2008 when he drove into the back of Kimi Raikkonen's Ferrari as the Finn waited at a red light at the pitlane exit, would certainly help.
Button was second last year in a McLaren one-two but has never won in North America, a situation he would also like to rectify.
"There's a real momentum within our team at the moment," he said after Monaco.
"I think we had a race car good enough to win in both Spain and Monaco; with a little improvement to our qualifying, I think we can start to dictate race pace, which was something we were briefly able to show at both of the last two races."
Ferrari, who had Alonso finish second in Monaco, will be pushing hard again and bringing some more developments to Canada.
"There is always a steady stream of updates coming through and this time we will have a few changes to the diffuser and rear wing, which will bring a reasonable performance step if everything goes to plan," chassis director Pat Fry told the team website (www.ferrari.com).
(Editing by Ed Osmond)